diff --git a/appinfo/routes.php b/appinfo/routes.php
index e06389476..3dc4df1d0 100644
--- a/appinfo/routes.php
+++ b/appinfo/routes.php
@@ -45,10 +45,12 @@
 		['name' => 'chattyLLM#newSession', 'url' => '/chat/sessions', 'verb' => 'POST', 'postfix' => 'restful'],
 		['name' => 'chattyLLM#updateChatSession', 'url' => '/chat/sessions/{sessionId}', 'verb' => 'PUT', 'postfix' => 'restful'],
 		['name' => 'chattyLLM#deleteSession', 'url' => '/chat/sessions/{sessionId}', 'verb' => 'DELETE', 'postfix' => 'restful'],
+		['name' => 'chattyLLM#deleteSessions', 'url' => '/chat/sessions', 'verb' => 'DELETE', 'postfix' => 'restful'],
 
 		['name' => 'chattyLLM#newSession', 'url' => '/chat/new_session', 'verb' => 'PUT'],
 		['name' => 'chattyLLM#updateSessionTitle', 'url' => '/chat/update_session', 'verb' => 'PATCH'],
 		['name' => 'chattyLLM#deleteSession', 'url' => '/chat/delete_session', 'verb' => 'DELETE'],
+		['name' => 'chattyLLM#deleteSessions', 'url' => '/chat/delete_sessions', 'verb' => 'DELETE'],
 		['name' => 'chattyLLM#getSessions', 'url' => '/chat/sessions', 'verb' => 'GET'],
 		['name' => 'chattyLLM#newMessage', 'url' => '/chat/new_message', 'verb' => 'PUT'],
 		['name' => 'chattyLLM#deleteMessage', 'url' => '/chat/delete_message', 'verb' => 'DELETE'],
diff --git a/lib/Controller/ChattyLLMController.php b/lib/Controller/ChattyLLMController.php
index 0772d325c..cc750a605 100644
--- a/lib/Controller/ChattyLLMController.php
+++ b/lib/Controller/ChattyLLMController.php
@@ -306,6 +306,36 @@ public function deleteSession(int $sessionId): JSONResponse {
 		}
 	}
 
+	/**
+	 * Delete chat sessions
+	 *
+	 * Delete several chat sessions by ID
+	 *
+	 * @param list<int> $sessionIds The session IDs
+	 * @return JSONResponse<Http::STATUS_OK, list{}, array{}>|JSONResponse<Http::STATUS_INTERNAL_SERVER_ERROR|Http::STATUS_UNAUTHORIZED|Http::STATUS_BAD_REQUEST, array{error: string}, array{}>
+	 *
+	 * 200: The sessions have been deleted successfully
+	 * 400: The list of session IDs is empty or invalid
+	 * 401: Not logged in
+	 */
+	#[NoAdminRequired]
+	#[OpenAPI(scope: OpenAPI::SCOPE_DEFAULT, tags: ['chat_api'])]
+	public function deleteSessions(array $sessionIds): JSONResponse {
+		if ($sessionIds === []) {
+			return new JSONResponse(['error' => $this->l10n->t('Invalid session IDs')], Http::STATUS_BAD_REQUEST);
+		}
+		try {
+			// we don't delete the tasks
+			$this->chatService->deleteSessions($this->userId, $sessionIds);
+			return new JSONResponse();
+		} catch (InternalException $e) {
+			$this->logger->warning('Failed to delete the chat sessions', ['exception' => $e]);
+			return new JSONResponse(['error' => $this->l10n->t('Failed to delete the chat sessions')], Http::STATUS_INTERNAL_SERVER_ERROR);
+		} catch (\OCA\Assistant\Service\UnauthorizedException $e) {
+			return new JSONResponse(['error' => $this->l10n->t('User not logged in')], Http::STATUS_UNAUTHORIZED);
+		}
+	}
+
 	/**
 	 * Get chat sessions
 	 *
diff --git a/lib/Db/ChattyLLM/MessageMapper.php b/lib/Db/ChattyLLM/MessageMapper.php
index 86204fc27..8b44208e5 100644
--- a/lib/Db/ChattyLLM/MessageMapper.php
+++ b/lib/Db/ChattyLLM/MessageMapper.php
@@ -177,6 +177,23 @@ public function deleteMessagesBySession(int $sessionId): void {
 		$qb->executeStatement();
 	}
 
+	/**
+	 * @param list<int> $sessionIds
+	 * @throws \OCP\DB\Exception
+	 * @throws \RuntimeException
+	 * @return void
+	 */
+	public function deleteMessagesBySessions(array $sessionIds): void {
+		$qb = $this->db->getQueryBuilder();
+		$qb->delete($this->getTableName())
+			->where($qb->expr()->in('session_id', $qb->createParameter('ids')));
+
+		foreach (array_chunk($sessionIds, IQueryBuilder::MAX_IN_PARAMETERS) as $chunk) {
+			$qb->setParameter('ids', $chunk, IQueryBuilder::PARAM_INT_ARRAY);
+			$qb->executeStatement();
+		}
+	}
+
 	/**
 	 * @param int $sessionId
 	 * @param integer $messageId
diff --git a/lib/Db/ChattyLLM/SessionMapper.php b/lib/Db/ChattyLLM/SessionMapper.php
index c8359173a..5c089c9bd 100644
--- a/lib/Db/ChattyLLM/SessionMapper.php
+++ b/lib/Db/ChattyLLM/SessionMapper.php
@@ -218,6 +218,43 @@ public function deleteSession(string $userId, int $sessionId) {
 		$qb->executeStatement();
 	}
 
+	/**
+	 * @param string $userId
+	 * @param list<int> $sessionIds
+	 * @return list<Session>
+	 * @throws \OCP\DB\Exception
+	 */
+	public function getUserSessionsByIds(string $userId, array $sessionIds): array {
+		$sessions = [];
+		foreach (array_chunk($sessionIds, IQueryBuilder::MAX_IN_PARAMETERS) as $chunk) {
+			$qb = $this->db->getQueryBuilder();
+			$qb->select(Session::$columns)
+				->from($this->getTableName())
+				->where($qb->expr()->eq('user_id', $qb->createPositionalParameter($userId, IQueryBuilder::PARAM_STR)))
+				->andWhere($qb->expr()->in('id', $qb->createPositionalParameter($chunk, IQueryBuilder::PARAM_INT_ARRAY)));
+			$sessions = array_merge($sessions, $this->findEntities($qb));
+		}
+		return $sessions;
+	}
+
+	/**
+	 * @param string $userId
+	 * @param list<int> $sessionIds
+	 * @throws \OCP\DB\Exception
+	 * @throws \RuntimeException
+	 */
+	public function deleteSessionsByUser(string $userId, array $sessionIds): void {
+		$qb = $this->db->getQueryBuilder();
+		$qb->delete($this->getTableName())
+			->where($qb->expr()->eq('user_id', $qb->createNamedParameter($userId, IQueryBuilder::PARAM_STR)))
+			->andWhere($qb->expr()->in('id', $qb->createParameter('ids')));
+
+		foreach (array_chunk($sessionIds, IQueryBuilder::MAX_IN_PARAMETERS) as $chunk) {
+			$qb->setParameter('ids', $chunk, IQueryBuilder::PARAM_INT_ARRAY);
+			$qb->executeStatement();
+		}
+	}
+
 	/**
 	 * @throws \OCP\DB\Exception
 	 */
diff --git a/lib/Service/ChatService.php b/lib/Service/ChatService.php
index 18adfc6c3..1f27de531 100644
--- a/lib/Service/ChatService.php
+++ b/lib/Service/ChatService.php
@@ -18,6 +18,7 @@
 use OCP\DB\Exception;
 use OCP\Exceptions\AppConfigTypeConflictException;
 use OCP\IAppConfig;
+use OCP\IDBConnection;
 use OCP\IL10N;
 use OCP\IUserManager;
 use OCP\TaskProcessing\Exception\PreConditionNotMetException;
@@ -36,6 +37,7 @@ public function __construct(
 		private readonly IL10N $l10n,
 		private readonly SessionMapper $sessionMapper,
 		private readonly MessageMapper $messageMapper,
+		private readonly IDBConnection $db,
 		private readonly SessionSummaryService $sessionSummaryService,
 		private readonly IManager $taskProcessingManager,
 		private readonly LoggerInterface $logger,
@@ -152,6 +154,47 @@ public function deleteSession(?string $userId, int $sessionId): void {
 		}
 	}
 
+	/**
+	 * @param string|null $userId
+	 * @param list<int> $sessionIds
+	 * @throws InternalException
+	 * @throws UnauthorizedException
+	 */
+	public function deleteSessions(?string $userId, array $sessionIds): void {
+		if ($userId === null) {
+			throw new UnauthorizedException($this->l10n->t('Unauthorized'));
+		}
+
+		$sessionIds = array_values(array_unique(array_map(static function ($sessionId) {
+			return (int)$sessionId;
+		}, $sessionIds)));
+
+		if ($sessionIds === []) {
+			return;
+		}
+
+		try {
+			$ownedSessions = $this->sessionMapper->getUserSessionsByIds($userId, $sessionIds);
+			$ownedSessionIds = array_map(static function (Session $session) {
+				return $session->getId();
+			}, $ownedSessions);
+
+			if ($ownedSessionIds === []) {
+				return;
+			}
+
+			$this->db->beginTransaction();
+			$this->sessionMapper->deleteSessionsByUser($userId, $ownedSessionIds);
+			$this->messageMapper->deleteMessagesBySessions($ownedSessionIds);
+			$this->db->commit();
+		} catch (Exception|\RuntimeException $e) {
+			if ($this->db->inTransaction()) {
+				$this->db->rollBack();
+			}
+			throw new InternalException(previous: $e);
+		}
+	}
+
 	/**
 	 * @throws InternalException
 	 */
diff --git a/openapi.json b/openapi.json
index ca07990e5..ec9569407 100644
--- a/openapi.json
+++ b/openapi.json
@@ -3818,6 +3818,138 @@
                     }
                 }
             },
+            "delete": {
+                "operationId": "chattyllm-delete-sessions-restful",
+                "summary": "Delete chat sessions",
+                "description": "Delete several chat sessions by ID",
+                "tags": [
+                    "chat_api"
+                ],
+                "security": [
+                    {
+                        "bearer_auth": []
+                    },
+                    {
+                        "basic_auth": []
+                    }
+                ],
+                "parameters": [
+                    {
+                        "name": "sessionIds[]",
+                        "in": "query",
+                        "description": "The session IDs",
+                        "required": true,
+                        "schema": {
+                            "type": "array",
+                            "items": {
+                                "type": "integer",
+                                "format": "int64"
+                            }
+                        }
+                    },
+                    {
+                        "name": "OCS-APIRequest",
+                        "in": "header",
+                        "description": "Required to be true for the API request to pass",
+                        "required": true,
+                        "schema": {
+                            "type": "boolean",
+                            "default": true
+                        }
+                    }
+                ],
+                "responses": {
+                    "200": {
+                        "description": "The sessions have been deleted successfully",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "type": "object"
+                                }
+                            }
+                        }
+                    },
+                    "500": {
+                        "description": "",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "type": "object",
+                                    "required": [
+                                        "error"
+                                    ],
+                                    "properties": {
+                                        "error": {
+                                            "type": "string"
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                    },
+                    "401": {
+                        "description": "Not logged in",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "anyOf": [
+                                        {
+                                            "type": "object",
+                                            "required": [
+                                                "error"
+                                            ],
+                                            "properties": {
+                                                "error": {
+                                                    "type": "string"
+                                                }
+                                            }
+                                        },
+                                        {
+                                            "type": "object",
+                                            "required": [
+                                                "ocs"
+                                            ],
+                                            "properties": {
+                                                "ocs": {
+                                                    "type": "object",
+                                                    "required": [
+                                                        "meta",
+                                                        "data"
+                                                    ],
+                                                    "properties": {
+                                                        "meta": {
+                                                            "$ref": "#/components/schemas/OCSMeta"
+                                                        },
+                                                        "data": {}
+                                                    }
+                                                }
+                                            }
+                                        }
+                                    ]
+                                }
+                            }
+                        }
+                    },
+                    "400": {
+                        "description": "The list of session IDs is empty or invalid",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "type": "object",
+                                    "required": [
+                                        "error"
+                                    ],
+                                    "properties": {
+                                        "error": {
+                                            "type": "string"
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            },
             "get": {
                 "operationId": "chattyllm-get-sessions",
                 "summary": "Get chat sessions",
@@ -4598,6 +4730,140 @@
                 }
             }
         },
+        "/ocs/v2.php/apps/assistant/chat/delete_sessions": {
+            "delete": {
+                "operationId": "chattyllm-delete-sessions",
+                "summary": "Delete chat sessions",
+                "description": "Delete several chat sessions by ID",
+                "tags": [
+                    "chat_api"
+                ],
+                "security": [
+                    {
+                        "bearer_auth": []
+                    },
+                    {
+                        "basic_auth": []
+                    }
+                ],
+                "parameters": [
+                    {
+                        "name": "sessionIds[]",
+                        "in": "query",
+                        "description": "The session IDs",
+                        "required": true,
+                        "schema": {
+                            "type": "array",
+                            "items": {
+                                "type": "integer",
+                                "format": "int64"
+                            }
+                        }
+                    },
+                    {
+                        "name": "OCS-APIRequest",
+                        "in": "header",
+                        "description": "Required to be true for the API request to pass",
+                        "required": true,
+                        "schema": {
+                            "type": "boolean",
+                            "default": true
+                        }
+                    }
+                ],
+                "responses": {
+                    "200": {
+                        "description": "The sessions have been deleted successfully",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "type": "object"
+                                }
+                            }
+                        }
+                    },
+                    "500": {
+                        "description": "",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "type": "object",
+                                    "required": [
+                                        "error"
+                                    ],
+                                    "properties": {
+                                        "error": {
+                                            "type": "string"
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                    },
+                    "401": {
+                        "description": "Not logged in",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "anyOf": [
+                                        {
+                                            "type": "object",
+                                            "required": [
+                                                "error"
+                                            ],
+                                            "properties": {
+                                                "error": {
+                                                    "type": "string"
+                                                }
+                                            }
+                                        },
+                                        {
+                                            "type": "object",
+                                            "required": [
+                                                "ocs"
+                                            ],
+                                            "properties": {
+                                                "ocs": {
+                                                    "type": "object",
+                                                    "required": [
+                                                        "meta",
+                                                        "data"
+                                                    ],
+                                                    "properties": {
+                                                        "meta": {
+                                                            "$ref": "#/components/schemas/OCSMeta"
+                                                        },
+                                                        "data": {}
+                                                    }
+                                                }
+                                            }
+                                        }
+                                    ]
+                                }
+                            }
+                        }
+                    },
+                    "400": {
+                        "description": "The list of session IDs is empty or invalid",
+                        "content": {
+                            "application/json": {
+                                "schema": {
+                                    "type": "object",
+                                    "required": [
+                                        "error"
+                                    ],
+                                    "properties": {
+                                        "error": {
+                                            "type": "string"
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        },
         "/ocs/v2.php/apps/assistant/chat/new_message": {
             "put": {
                 "operationId": "chattyllm-new-message",
diff --git a/src/components/ChattyLLM/ChattyLLMInputForm.vue b/src/components/ChattyLLM/ChattyLLMInputForm.vue
index 51da553de..401345e99 100644
--- a/src/components/ChattyLLM/ChattyLLMInputForm.vue
+++ b/src/components/ChattyLLM/ChattyLLMInputForm.vue
@@ -6,7 +6,7 @@
 	<div class="container">
 		<NcAppNavigation>
 			<NcAppNavigationList>
-				<NcAppNavigationNew v-if="!isAssignment"
+				<NcAppNavigationNew v-if="!isAssignment && !deletionMode"
 					:text="t('assistant', 'New conversation')"
 					variant="secondary"
 					@click="newSession">
@@ -14,6 +14,40 @@
 						<PlusIcon :size="20" />
 					</template>
 				</NcAppNavigationNew>
+				<NcButton v-if="!isAssignment && !deletionMode && (sessions?.length ?? 0) > 0"
+					class="deletion-mode-button"
+					variant="secondary"
+					@click="enterDeletionMode()">
+					<template #icon>
+						<DeleteSweepOutlineIcon :size="20" />
+					</template>
+					{{ t('assistant', 'Delete multiple conversations') }}
+				</NcButton>
+				<div v-if="deletionMode" class="deletion-mode-bar">
+					<div class="deletion-mode-bar__first-line">
+						<NcButton :disabled="loading.sessionsDelete"
+							variant="secondary"
+							@click="toggleSelectAll">
+							{{ selectAllLabel }}
+						</NcButton>
+						<NcButton :disabled="loading.sessionsDelete"
+							variant="secondary"
+							@click="exitDeletionMode">
+							{{ t('assistant', 'Cancel') }}
+						</NcButton>
+					</div>
+					<NcButton v-if="selectedSessionIds.length > 0"
+						:disabled="loading.sessionsDelete"
+						variant="error"
+						class="deletion-mode-bar__delete"
+						@click="openDeletionDialog([...selectedSessionIds])">
+						<template #icon>
+							<TrashCanOutlineIcon v-if="!loading.sessionsDelete" :size="20" />
+							<NcLoadingIcon v-else :size="20" />
+						</template>
+						{{ deleteSelectedLabel }}
+					</NcButton>
+				</div>
 				<div v-if="sessions == null" class="unloaded-sessions">
 					<NcLoadingIcon :size="30" />
 					{{ isAssignment ? t('assistant', 'Loading scheduled tasks…') : t('assistant', 'Loading conversations…') }}
@@ -25,17 +59,17 @@
 					v-for="session in sessions"
 					v-else
 					:key="'conversation' + session.id"
-					:active="session.id === active?.id"
+					:active="deletionMode ? selectedSessionIds.includes(session.id) : session.id === active?.id"
 					:name="getSessionTitle(session)"
 					:title="getSessionTitle(session)"
 					:aria-description="getSessionTitle(session)"
 					:editable="false"
 					:inline-actions="1"
-					@click="onSessionSelect(session)">
+					@click="deletionMode ? toggleSessionSelection(session.id) : onSessionSelect(session)">
 					<template #actions>
-						<NcActionButton @click="sessionIdToDelete = session.id">
+						<NcActionButton @click="openDeletionDialog([session.id])">
 							<template #icon>
-								<TrashCanOutlineIcon v-if="!loading.sessionDelete" :size="20" />
+								<TrashCanOutlineIcon v-if="!loading.sessionsDelete" :size="20" />
 								<NcLoadingIcon v-else :size="20" />
 							</template>
 							{{ t('assistant', 'Delete') }}
@@ -198,22 +232,21 @@
 				@submit="handleSubmit"
 				@submit-audio="handleSubmitAudio" />
 		</NcAppContent>
-		<NcDialog :open="sessionIdToDelete !== null"
+		<NcDialog :key="deletionDialogKey"
+			v-model:open="deletionDialogOpen"
 			:name="t('assistant', 'Conversation deletion')"
 			:message="deletionConfirmationMessage"
 			:container="null"
-			@closing="sessionIdToDelete = null">
+			@closing="sessionIdsToDelete = null">
 			<template #actions>
 				<NcButton
-					@click="sessionIdToDelete = null">
+					variant="secondary"
+					@click="sessionIdsToDelete = null">
 					{{ t('assistant', 'Cancel') }}
 				</NcButton>
 				<NcButton
-					variant="warning"
-					@click="deleteSession(sessionIdToDelete)">
-					<template #icon>
-						<TrashCanOutlineIcon />
-					</template>
+					variant="error"
+					@click="deleteSessions(sessionIdsToDelete)">
 					{{ t('assistant', 'Delete') }}
 				</NcButton>
 			</template>
@@ -226,6 +259,7 @@ import AutoFixIcon from 'vue-material-design-icons/AutoFix.vue'
 import PencilOutlineIcon from 'vue-material-design-icons/PencilOutline.vue'
 import PlusIcon from 'vue-material-design-icons/Plus.vue'
 import TrashCanOutlineIcon from 'vue-material-design-icons/TrashCanOutline.vue'
+import DeleteSweepOutlineIcon from 'vue-material-design-icons/DeleteSweepOutline.vue'
 import MemoryIcon from 'vue-material-design-icons/Memory.vue'
 import TimerOutlineIcon from 'vue-material-design-icons/TimerOutline.vue'
 
@@ -282,6 +316,7 @@ export default {
 		AgencyConfirmation,
 		AutoFixIcon,
 		TrashCanOutlineIcon,
+		DeleteSweepOutlineIcon,
 		PencilOutlineIcon,
 		PlusIcon,
 		MemoryIcon,
@@ -324,7 +359,10 @@ export default {
 		return {
 			// { id: number, title: string, user_id: string, timestamp: number }
 			active: null,
-			sessionIdToDelete: null,
+			sessionIdsToDelete: null,
+			deletionDialogKey: 0,
+			deletionMode: false,
+			selectedSessionIds: [],
 			chatContent: '',
 			sessions: null,
 			assignmentDetails: null,
@@ -349,7 +387,7 @@ export default {
 				newHumanMessage: false,
 				newSession: false,
 				messageDelete: false,
-				sessionDelete: false,
+				sessionsDelete: false,
 				taskPosition: null,
 			},
 			msgCursor: 0,
@@ -413,13 +451,39 @@ export default {
 	},
 
 	computed: {
+		deletionDialogOpen: {
+			get() {
+				return this.sessionIdsToDelete !== null
+			},
+			set(value) {
+				if (!value) {
+					this.sessionIdsToDelete = null
+				}
+			},
+		},
 		deletionConfirmationMessage() {
-			if (this.sessions === null || this.sessionIdToDelete === null) {
+			if (this.sessions === null || this.sessionIdsToDelete === null || this.sessionIdsToDelete.length === 0) {
 				return ''
 			}
-			const session = this.sessions.find(s => s.id === this.sessionIdToDelete)
-			const sessionTitle = this.getSessionTitle(session)?.trim()
-			return t('assistant', 'Are you sure you want to delete "{sessionTitle}"?', { sessionTitle })
+			if (this.sessionIdsToDelete.length === 1) {
+				const session = this.sessions.find(s => s.id === this.sessionIdsToDelete[0])
+				if (session) {
+					const sessionTitle = this.getSessionTitle(session)?.trim()
+					return t('assistant', 'Are you sure you want to delete "{sessionTitle}"?', { sessionTitle })
+				}
+			}
+			return n('assistant', 'Are you sure you want to delete %n conversation?', 'Are you sure you want to delete %n conversations?', this.sessionIdsToDelete.length)
+		},
+		deleteSelectedLabel() {
+			return n('assistant', 'Delete %n conversation', 'Delete %n conversations', this.selectedSessionIds.length)
+		},
+		selectAllLabel() {
+			return this.allSessionsSelected ? t('assistant', 'Deselect all') : t('assistant', 'Select all')
+		},
+		allSessionsSelected() {
+			return this.sessions !== null
+				&& this.sessions.length > 0
+				&& this.selectedSessionIds.length === this.sessions.length
 		},
 		rrule() {
 			const raw = this.assignmentDetails?.recurrence ?? ''
@@ -484,11 +548,19 @@ export default {
 			this.active = null
 			clearTimeout(this.pollCheckSessionTimeout)
 		},
+		deletionMode(enabled) {
+			if (enabled) {
+				window.addEventListener('keydown', this.onKeydownEscape, true)
+			} else {
+				window.removeEventListener('keydown', this.onKeydownEscape, true)
+			}
+		},
 	},
 
 	beforeUnmount() {
 		this.pollMessageGenerationCancel?.()
 		cancelTaskPositionPolling()
+		window.removeEventListener('keydown', this.onKeydownEscape, true)
 		if (this.pollMessageGenerationTimerId) {
 			clearInterval(this.pollMessageGenerationTimerId)
 		}
@@ -684,7 +756,7 @@ export default {
 		 * @param {{ id: number, title: string, user_id: string, timestamp: number }} session Chat session
 		 */
 		getSessionTitle(session) {
-			if (session === null) {
+			if (session === null || session === undefined) {
 				return ''
 			}
 
@@ -781,22 +853,67 @@ export default {
 			}
 		},
 
-		async deleteSession(sessionId) {
+		enterDeletionMode() {
+			this.selectedSessionIds = []
+			this.deletionMode = true
+		},
+
+		exitDeletionMode() {
+			this.deletionMode = false
+			this.selectedSessionIds = []
+		},
+
+		openDeletionDialog(sessionIds) {
+			this.deletionDialogKey++
+			this.sessionIdsToDelete = sessionIds
+		},
+
+		onKeydownEscape(event) {
+			if (event.key !== 'Escape' || this.sessionIdsToDelete !== null) {
+				return
+			}
+			this.exitDeletionMode()
+		},
+
+		toggleSessionSelection(sessionId) {
+			if (this.selectedSessionIds.includes(sessionId)) {
+				this.selectedSessionIds = this.selectedSessionIds.filter(id => id !== sessionId)
+			} else {
+				this.selectedSessionIds.push(sessionId)
+			}
+		},
+
+		toggleSelectAll() {
+			if (this.allSessionsSelected) {
+				this.selectedSessionIds = []
+			} else {
+				this.selectedSessionIds = this.sessions.map(session => session.id)
+			}
+		},
+
+		async deleteSessions(sessionIds) {
+			if (!Array.isArray(sessionIds) || sessionIds.length === 0) {
+				this.sessionIdsToDelete = null
+				return
+			}
 			try {
-				this.loading.sessionDelete = true
-				await axios.delete(getChatURL('/delete_session'), {
-					params: { sessionId },
+				this.loading.sessionsDelete = true
+				await axios.delete(getChatURL('/delete_sessions'), {
+					params: { sessionIds },
 				})
-				this.sessions = this.sessions.filter((session) => session.id !== sessionId)
-				if (this.active?.id === sessionId) {
+				this.sessions = this.sessions.filter((session) => !sessionIds.includes(session.id))
+				if (this.active !== null && sessionIds.includes(this.active.id)) {
 					this.active = null
 				}
+				if (this.deletionMode) {
+					this.exitDeletionMode()
+				}
 			} catch (error) {
-				console.error('deleteSession error:', error)
-				showError(error?.response?.data?.error ?? t('assistant', 'Error deleting conversation'))
+				console.error('deleteSessions error:', error)
+				showError(error?.response?.data?.error ?? t('assistant', 'Error deleting conversations'))
 			} finally {
-				this.loading.sessionDelete = false
-				this.sessionIdToDelete = null
+				this.loading.sessionsDelete = false
+				this.sessionIdsToDelete = null
 			}
 		},
 
@@ -1318,6 +1435,31 @@ export default {
 		height: 100%;
 	}
 
+	.deletion-mode-button {
+		width: 100%;
+	}
+
+	.deletion-mode-bar {
+		display: flex;
+		flex-direction: column;
+		gap: var(--default-grid-baseline);
+		padding: 0;
+
+		&__first-line {
+			display: flex;
+			align-items: center;
+			gap: var(--default-grid-baseline);
+
+			:deep(button) {
+				flex: 1 1 0;
+			}
+		}
+
+		&__delete {
+			width: 100%;
+		}
+	}
+
 	:deep(.app-navigation) {
 		--app-navigation-max-width: calc(100vw - (var(--app-navigation-padding) + 24px + var(--default-grid-baseline)));
 		background-color: var(--color-primary-element-light);
diff --git a/tests/unit/Service/ChatServiceTest.php b/tests/unit/Service/ChatServiceTest.php
new file mode 100644
index 000000000..eb784c6c9
--- /dev/null
+++ b/tests/unit/Service/ChatServiceTest.php
@@ -0,0 +1,159 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Assistant\Tests\Unit\Service;
+
+use OCA\Assistant\Db\ChattyLLM\Message;
+use OCA\Assistant\Db\ChattyLLM\MessageMapper;
+use OCA\Assistant\Db\ChattyLLM\Session;
+use OCA\Assistant\Db\ChattyLLM\SessionMapper;
+use OCA\Assistant\Service\ChatService;
+use OCA\Assistant\Service\UnauthorizedException;
+use OCP\IUserManager;
+use OCP\Server;
+use Test\TestCase;
+
+/**
+ * Integration tests for the ChatService chat session deletion methods.
+ *
+ * Runs against a real Nextcloud test server with a real database.
+ * Creates dedicated test users and cleans up all chat data in tearDown.
+ *
+ * @group DB
+ */
+class ChatServiceTest extends TestCase {
+
+	private const TEST_USER = 'chat_service_test_user';
+	private const OTHER_USER = 'chat_service_other_user';
+
+	private ChatService $service;
+	private SessionMapper $sessionMapper;
+	private MessageMapper $messageMapper;
+	/** @var list<string> user IDs created by this test, deleted again in tearDown */
+	private array $createdUsers = [];
+	/** @var array<string, list<int>> session IDs created by this test, per user ID */
+	private array $createdSessionIds = [];
+
+	protected function setUp(): void {
+		parent::setUp();
+
+		/** @var IUserManager $userManager */
+		$userManager = Server::get(IUserManager::class);
+		foreach ([self::TEST_USER, self::OTHER_USER] as $uid) {
+			if (!$userManager->userExists($uid)) {
+				$userManager->createUser($uid, $uid . '_password123');
+				$this->createdUsers[] = $uid;
+			}
+		}
+
+		$this->service = Server::get(ChatService::class);
+		$this->sessionMapper = Server::get(SessionMapper::class);
+		$this->messageMapper = Server::get(MessageMapper::class);
+	}
+
+	protected function tearDown(): void {
+		// only remove what this test created, the instance is not always in a clean state in CI
+		foreach ($this->createdSessionIds as $uid => $sessionIds) {
+			foreach ($sessionIds as $sessionId) {
+				$this->sessionMapper->deleteSession($uid, $sessionId);
+				$this->messageMapper->deleteMessagesBySession($sessionId);
+			}
+		}
+		$userManager = Server::get(IUserManager::class);
+		foreach ($this->createdUsers as $uid) {
+			if ($userManager->userExists($uid)) {
+				$this->service->deleteAllUserChatData($uid);
+				$userManager->get($uid)->delete();
+			}
+		}
+		parent::tearDown();
+	}
+
+	private function createSession(string $userId): Session {
+		$session = new Session();
+		$session->setUserId($userId);
+		$session->setTimestamp(time());
+		$session = $this->sessionMapper->insert($session);
+		$this->createdSessionIds[$userId][] = $session->getId();
+		return $session;
+	}
+
+	private function createMessage(int $sessionId): Message {
+		$message = new Message();
+		$message->setSessionId($sessionId);
+		$message->setRole(Message::ROLE_HUMAN);
+		$message->setAttachments('[]');
+		$message->setContent('test message');
+		$message->setSources('[]');
+		$message->setTimestamp(time());
+		return $this->messageMapper->insert($message);
+	}
+
+	public function testDeleteSessions(): void {
+		$session1 = $this->createSession(self::TEST_USER);
+		$session2 = $this->createSession(self::TEST_USER);
+		$session3 = $this->createSession(self::TEST_USER);
+		$this->createMessage($session1->getId());
+		$this->createMessage($session2->getId());
+		$this->createMessage($session3->getId());
+
+		$this->service->deleteSessions(self::TEST_USER, [$session1->getId(), $session2->getId(), $session3->getId()]);
+
+		$remainingIds = array_map(static function (Session $session) {
+			return $session->getId();
+		}, $this->sessionMapper->getUserSessions(self::TEST_USER, false));
+		$this->assertNotContains($session1->getId(), $remainingIds);
+		$this->assertNotContains($session2->getId(), $remainingIds);
+		$this->assertNotContains($session3->getId(), $remainingIds);
+		$this->assertCount(0, $this->messageMapper->getMessages($session1->getId(), 0, 100));
+		$this->assertCount(0, $this->messageMapper->getMessages($session2->getId(), 0, 100));
+		$this->assertCount(0, $this->messageMapper->getMessages($session3->getId(), 0, 100));
+	}
+
+	public function testDeleteSessionsLeavesOtherUsersDataAlone(): void {
+		$ownSession = $this->createSession(self::TEST_USER);
+		$otherSession = $this->createSession(self::OTHER_USER);
+		$this->createMessage($ownSession->getId());
+		$otherMessage = $this->createMessage($otherSession->getId());
+
+		// the other user's session ID is passed but must not be deleted,
+		// unknown IDs are ignored, duplicates are harmless
+		$this->service->deleteSessions(self::TEST_USER, [$ownSession->getId(), $otherSession->getId(), $otherSession->getId(), 999999999]);
+
+		$remainingOwnIds = array_map(static function (Session $session) {
+			return $session->getId();
+		}, $this->sessionMapper->getUserSessions(self::TEST_USER, false));
+		$this->assertNotContains($ownSession->getId(), $remainingOwnIds);
+		$this->assertCount(0, $this->messageMapper->getMessages($ownSession->getId(), 0, 100));
+
+		$remainingOtherIds = array_map(static function (Session $session) {
+			return $session->getId();
+		}, $this->sessionMapper->getUserSessions(self::OTHER_USER, false));
+		$this->assertContains($otherSession->getId(), $remainingOtherIds);
+		$this->assertContains($otherMessage->getContent(), array_map(static function (Message $message) {
+			return $message->getContent();
+		}, $this->messageMapper->getMessages($otherSession->getId(), 0, 100)));
+	}
+
+	public function testDeleteSessionsWithEmptyList(): void {
+		$session = $this->createSession(self::TEST_USER);
+
+		$this->service->deleteSessions(self::TEST_USER, []);
+
+		$remainingIds = array_map(static function (Session $session) {
+			return $session->getId();
+		}, $this->sessionMapper->getUserSessions(self::TEST_USER, false));
+		$this->assertContains($session->getId(), $remainingIds);
+	}
+
+	public function testDeleteSessionsWithoutUser(): void {
+		$this->expectException(UnauthorizedException::class);
+		$this->service->deleteSessions(null, [1, 2]);
+	}
+}