22 October 2026 · 3 min read

Break down any video frame by frame, and check yours before posting

video-check is a free skill for Claude Code. It breaks down any vertical video frame by frame (hook, cuts, pacing, captions) and checks yours before you post: text hidden by the buttons, silence at the start, sound, colours. Copy this message, paste it into Claude Code, and it installs everything.

Contact sheet from the analysis: 18 frames of the video, one every half second, each with its timestamp. — A contact sheet from the analysis: 2 frames per second, with timestamps (here, my « page HTML » video). Claude looks at them one by one.

video-checkThe code and the docs, on GitHub. Free and open source.github.com/pjksens/video-check

The prompt

Paste it into Claude Code (in the terminal, or in the Claude app, Code tab). Claude will ask you to allow each command: read it, then allow it.

Install the video-check skill on my Mac (https://github.com/pjksens/video-check). Do every step yourself, in order. If a step fails, stop and tell me why.

1. Check that I'm on macOS (`sw_vers -productVersion`). If not, stop: this skill only works on a Mac.
2. Download the skill: `git clone https://github.com/pjksens/video-check ~/.claude/skills/video-check` (if it's already there, update it with `git -C ~/.claude/skills/video-check pull`).
3. Run `bash ~/.claude/skills/video-check/install.sh`. If it asks for Apple's tools (`xcode-select --install`) or Homebrew, tell me exactly what to do, wait until I say "done", then run it again.
4. Check that everything works: `~/.claude/skills/video-check/.venv/bin/python ~/.claude/skills/video-check/scripts/controle.py --help` must print the help.
5. Finally, tell me in 3 lines the 2 sentences to say to you: "analyse this video: <file>" and "check my video before I post it: <file>", and that I should restart Claude Code if the skill doesn't show up yet.
6. Last, ask me if I want to star the GitHub repo. Only if I say yes: if `gh auth status` shows a logged-in account, run `gh api -X PUT /user/starred/pjksens/video-check`; otherwise, give me the link https://github.com/pjksens/video-check.

What Claude does for you

1.Checks that you are on a Mac, then downloads the skill into Claude Code’s skills folder.
2.Installs what it needs: ffmpeg (if missing), a separate Python environment, Apple’s text recognition and Whisper for speech (about 460 MB, once).
3.Checks that everything works, then tells you the 2 sentences to say.

What’s left for you

1.If macOS asks
Install Apple’s tools (a window opens, a few minutes), then tell Claude "done".
```
xcode-select --install
```
2.Analyse a video
The video must be on your Mac: the skill doesn’t download anything. Then tell Claude:
```
Analyse this video: ~/Downloads/reel.mp4
```

3.Check yours

Right before posting:

Check my video before I post it: ~/Movies/my-video.mp4

Frequently asked questions

How much does it cost?+

video-check is free and open source (MIT licence). Claude Code needs a paid Claude plan (Pro at least).

Which computer?+

Mac only: reading on-screen text uses Apple’s text recognition.

Does my video go online?+

No: the measurements (cuts, on-screen text, speech, loudness) run on your Mac. Claude then looks at the contact sheets and the report to answer you: those images go through Anthropic, like any image you show Claude.

Will it tell me if my video will get views?+

No. It measures and flags specific problems (text hidden by the buttons, silence at the start, low sound, a long stretch with no change…). It doesn’t judge your idea.

Can I analyse another creator’s video?+

Yes, if you have the file: to understand how it’s edited and learn from it, not to repost it.

How long does it take?+

About 1 minute to check a 40-second video, 2 minutes to analyse it frame by frame in 4K.

star it on GitHub1 star

Is video-check useful to you? A star helps other creators find it.

A question? Ask in the comments under the video, or open an issue on GitHub.