logview

A premium terminal log viewer for live-tailing, filtering, and exploring log files. Built in Go with Bubble Tea and Lip Gloss.

 ▌ logview │ test.log                                  18 lines · upd now
   ● INFO 421   ▲ WARN 87   ✖ ERROR 12   ⚠ FATAL 0   ● DEBUG 42
   ████████████████████████████████████████████████████████████████████████
    10:23:14  ●  INFO   Server started on port 3000
    10:23:15  ●  INFO   Connection accepted from 192.168.1.5
  ★ 10:23:16  ▲  WARN   High memory usage detected
  ▎ 10:23:17  ✖  ERROR  Timeout after 30s
    10:23:18  ●  INFO   Retrying connection...
   ─────────────────────────────────────────────────────────────────────
   /payment   3/421 · follow ON · ★ 1                              ? help

Features

• Live tail — watches the file via fsnotify and auto-scrolls on append.
• Stdin mode — pipe anything in with tail -f x.log | logview -.
• Pause the display while the file keeps growing in the background.
• Filter by substring or regex, with an inverse mode (!prefix) and a filter history (↑/↓).
• Level toggles — hide/show INFO, WARN, ERROR, DEBUG independently.
• Jump between errors — n / N cycles through ERROR and FATAL lines.
• Bookmarks — mark any line and cycle through them with ] / [.
• Detail view — open the full parsed line in a centered card.
• Export the current filtered view to <file>.filtered.log.
• Timestamp parsing — recognises HH:MM:SS[.fff] and ISO 8601 prefixes and dims them so the message stands out.
• Premium UI — Catppuccin Mocha palette, proportional level bar, level chips, cursor highlight, rounded cards for detail/help.

Install

From source

Requires Go 1.21+ (developed against Go 1.26).

go install github.com/yagofontanez/logview@latest

Build locally

git clone https://github.com/yagofontanez/logview.git
cd logview
go build -o logview .
./logview test.log

Usage

logview <file>          # open and follow a file
logview -               # read from stdin (keyboard still works via /dev/tty)

# pipe examples
tail -f /var/log/syslog | logview -
journalctl -f           | logview -
kubectl logs -f my-pod  | logview -

When stdin closes, the header shows stdin · EOF and the buffer stays open for browsing.

Keyboard shortcuts

Navigation

Key	Action
j k / ↑ ↓	move cursor one line
g / G	go to top / bottom
PgUp / PgDn	scroll one page
Enter	open detail view for selected line
Esc	close detail / clear active filter

Filtering

Key	Action
/	open the filter prompt
Ctrl+R	toggle substring ↔ regex (while editing the filter)
↑ / ↓	cycle filter history (while editing the filter)
Enter	apply filter and exit prompt
Esc	cancel filter prompt and clear the active filter
!prefix	inverse filter (e.g. !INFO hides lines with INFO)

Levels

Key	Action
i / w / e / D	hide/show INFO / WARN / ERROR / DEBUG
n / N	next / previous ERROR or FATAL line

Bookmarks

Key	Action
m	toggle bookmark on the cursor line
] / [	jump to next / previous bookmark

Display

Key	Action
f	toggle follow (tail) mode
p	pause / resume display updates
L	toggle line numbers

App

Key	Action
x	export current filtered view to .filtered.log
?	toggle the help card
q / Ctrl+C	quit

Log level detection

A line is classified by the first match of these substrings:

FATAL → ERROR → WARN → INFO → DEBUG (everything else is OTHER)

Timestamps are recognised when the line starts with either:

• HH:MM:SS (optionally followed by .fff or ,fff)
• YYYY-MM-DD[T ]HH:MM:SS[.fff][Z|±HH:MM] (ISO 8601)

The detected timestamp is rendered in a dim column so the rest of the line keeps its level colour.

Filter syntax

Filter	Meaning
(empty)	show all lines
payment	case-insensitive substring match
!INFO	inverse — hide lines that contain INFO
(regex mode)	the filter is compiled as a case-insensitive Go regex
!^[ \t]*#	combine inverse + regex (hide commented lines)

Toggle regex mode with Ctrl+R while the filter prompt is open. An invalid regex is reported in the status bar without crashing the view.

Project layout

.
├── main.go        # the entire program
├── go.mod
├── go.sum
├── test.log       # small sample input
└── README.md

License

MIT — see LICENSE if present, otherwise feel free to use under MIT terms.