✂️ YT Clipmaker

Cut exact clips out of YouTube videos and hand them to DaVinci Resolve, edit-ready.

A local web app that wraps yt-dlp and ffmpeg in a frame-accurate trimming UI — no uploads, no ads, no sketchy download sites. Everything stays on your machine.

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Why

Downloading a whole 40-minute video to use six seconds of it is a waste of time and disk. YT Clipmaker lets you scrub to the exact moment, set in/out points on a zoomable timeline, and pull down only that range — already transcoded to a codec your NLE actually enjoys working with.

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Features

🎯 Frame-accurate trimming	Step frame by frame with the arrow keys. The real frame rate is read from the video's metadata.
🔍 Zoomable timeline	Scroll to zoom, Shift+scroll to pan, drag the overview strip below. Zoom in far enough and the ruler switches to milliseconds.
🚩 Flagged in/out handles	IN and OUT markers carry labelled flags, so they are easy to grab — and the playhead always draws on top of them.
🎨 Colour-coded selection	The I→O range gets its own colour, clearly separate from the orange playback progress.
⭐ Starred export options	Pin the resolutions and formats you actually use; they sort to the top of the dropdown and persist.
🎬 Resolve-ready output	Export straight to DNxHR HQ or ProRes 422 with PCM audio — no more media-pool surprises.
📋 Segment queue	Mark several ranges in one video, then export them all in one go.
📊 Live download queue	Progress, speed and ETA per job, with cancel and Show in Explorer.
↩️ Undo / redo	Every in/out placement and segment edit is undoable with Ctrl+Z — and redoable with Ctrl+Y.
🎨 Four colour themes	Orange or green, each in dark and light. Saved with the rest of your settings.
🕘 History	The last 12 videos with thumbnails — individually removable.
⌨️ Keyboard-first	Every action has a shortcut. Press ? for the full list.
🌍 English & German	Switch in the settings; the choice is saved.

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Requirements

Tool	Purpose	Install
Python 3.10+	Runs the backend	python.org
yt-dlp	Metadata + section download	winget install yt-dlp
FFmpeg	Muxing, keyframe cuts, transcoding	winget install Gyan.FFmpeg

yt-dlp and ffmpeg are located through your PATH, so keeping them updated through your package manager is all the maintenance they need.

Note — The reveal-in-Explorer and folder-picker features are Windows-specific. Everything else is cross-platform.

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Quick start

pip install fastapi "uvicorn[standard]"
python app.py

The app opens at http://127.0.0.1:8321 automatically. On Windows you can also just double-click start.bat.

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Usage

1. Paste a YouTube URL into the top bar — it loads on paste, no click needed. Accepts watch?v=, youtu.be, /shorts/, /live/ and bare 11-character IDs.
2. Set the range. Press I and O at the playhead, drag the flagged handles, or type a timecode into the fields — 90, 1:30, 00:01:30.500 and 1m30s are all understood.
3. Pick resolution and format in the sidebar. Star the ones you reach for often.
4. Export. Watch it in the download queue, then hit Show in Explorer or Copy path and drag the file into your Resolve media pool.

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Export formats

Format	Codec	Use it when
MP4	H.264 + AAC	Default. Smallest file, fastest export, no transcode step.
MOV — DNxHR HQ	DNxHR HQ + PCM	Recommended for Resolve on Windows. Smooth scrubbing, no audio surprises.
MOV — ProRes 422	ProRes 422 + PCM	Your project already runs on ProRes.
M4A	AAC	Audio only.

DNxHR and ProRes are transcoded locally after the download; the source MP4 is kept alongside the result.

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Keyboard shortcuts

Playback	Trimming
Key Action Space K Play / pause ← → One frame Shift + ← → One second Ctrl + ← → Ten seconds J L ±5 seconds Home End Start / end 1…9 Jump to 10 %…90 % M Mute + − Playback speed	Key Action I O Set in / out point Shift+I O Jump to in / out X Reset selection P Loop the selection Z Shift+Z Zoom in / out F Fit view to selection Shift+F Show whole video A Save as segment Enter Export clip Ctrl+Z / Ctrl+Y Undo / redo

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Settings

Stored in settings.json next to app.py, so they survive browser restarts and cache clears.

Setting	Default	Notes
language	en	en or de
theme	orange-dark	orange-dark, orange-light, green-dark, green-light
resolution	1080	Falls back to the next available height per video
container	mp4	mp4, dnxhr, prores, audio
output_dir	~/Documents/Video/Clips	Pick it through the native folder dialog
prefer_h264	true	Avoids VP9/AV1 — Resolve is much happier with H.264
force_keyframes	true	Exact cut edges instead of up to 10 s of drift
restrict_filenames	true	ASCII-safe names, avoids media-pool issues
concurrent_fragments	4	Parallel download fragments
fav_resolutions / fav_containers	[]	Starred options, sorted to the top

Themes

Four schemes, switchable under ⚙ → Colour theme:

Theme	Accent	Surface
Orange · Dark (default)	#ff7a35	near-black
Orange · Light	#d95c0c	warm white
Green · Dark	#1bd96a	cool grey
Green · Light	#009f52	soft mint white

Every colour in the stylesheet resolves from CSS custom properties on :root, so adding a fifth theme is one override block in style.css plus one entry in the THEMES array in app.js.

Undo / redo

The editor keeps up to 100 snapshots of the in/out points and the segment list. Zoom and playback position are deliberately excluded — undoing a zoom would be noise rather than help. Loading a new video starts a fresh stack, and making an edit after undoing discards the redo branch, exactly as you would expect.

Language

English is the default. Switch to German under ⚙ → Language; the choice is written to settings.json immediately and applies without a reload.

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Project layout

.
├── app.py              FastAPI backend, job queue, yt-dlp/ffmpeg orchestration
├── start.bat           Windows launcher
├── settings.json       Generated on first run
└── static/
    ├── index.html      Markup
    ├── style.css       Dark UI theme
    ├── i18n.js         EN/DE strings
    └── app.js          Player, timeline, zoom, export logic

API

Method	Endpoint	Purpose
GET POST	/api/settings	Read / patch settings
POST	/api/info	Video metadata (duration, fps, heights, chapters)
GET POST	/api/jobs	List / create export jobs
POST	/api/jobs/{id}/cancel	Cancel a running job
DELETE	/api/jobs/{id}	Remove a job from the list
DELETE	/api/recents/{id}	Remove one history entry
DELETE	/api/recents	Clear the history
POST	/api/reveal	Open the output folder in Explorer
POST	/api/pick-folder	Native folder picker
GET	/api/health	Resolved yt-dlp / ffmpeg paths

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Limitations

• The preview player is a YouTube embed. Frame stepping gets very close, but YouTube seeks to the nearest reachable point internally, so it is not guaranteed to be frame-exact. The download cuts exactly, because --force-keyframes-at-cuts places real keyframes at the cut edges.
• The resolution picker controls the download, not the preview quality — YouTube decides that itself inside the embed.
• Videos with embedding disabled show no preview, but still export fine.

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Legal

YouTube's Terms of Service only permit downloads through their own offline feature. Use this for content you own, Creative Commons material, or where local law grants you an exception (quotation, private copy). That call is yours to make.

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_{Built with FastAPI · yt-dlp · FFmpeg}