Compress and convert video and audio on your own computer. Free and open source, for Windows, macOS and Linux. Nothing is uploaded anywhere, there are no file size limits, and you need to know nothing about codecs.
It needs the internet once, and then never again. On first run it fetches ffmpeg into its own folder. After that you can turn the network off and HalveIt keeps working, on a plane, on a train, or on a machine that has never been online.
That is the real difference from a converter on the web. Those want the file uploaded first, which puts your holiday videos or your recordings on somebody else's server, under their size limits, their queue, their privacy policy and their decision about how long to keep a copy. Nothing you convert here leaves the computer, because there is nowhere for it to go.
Double-click one file. HalveIt opens in your browser. Choose your files, pick what you want, press Compress. If a tool it needs is missing, it offers to fetch that tool and keeps it inside its own folder.
People who prefer a terminal get every feature as command line flags.
| Kind | Reads | Writes |
|---|---|---|
| Video | MP4, MOV, MKV, AVI, WebM, MPEG, WMV, FLV and more | MP4, MKV, WebM, MOV in H.265, H.264, AV1, VP9 |
| Audio | MP3, M4A, AAC, WAV, FLAC, OGG, Opus, WMA, AIFF | Opus, AAC, MP3, FLAC |
HalveIt asks what you would like to do, and shows you the settings for that job rather than all of them at once.
Eight jobs for video. Every one of them was possible before it had a name.
Three files added, and the presets for the job you chose. The job sits in the header, with a way to change it.
The result beside the original, so you can see for yourself what the saving cost.
Stills and camera RAW are being worked on and are not in this version. They were close, but not close enough to hand somebody a wedding shoot and tell them it was fine, so they wait. When they arrive it will be as a release of its own, with measurements published alongside it rather than a promise.
Video and audio are finished work, and are what this version does.
Documentation: User guide · Everything it can do · What changed · Audio
Put the HalveIt folder somewhere permanent before you use it:
| System | Suggested location |
|---|---|
| Windows | C:\Users\<you>\Documents\HalveIt |
| macOS | ~/Documents/HalveIt |
| Linux | ~/Documents/HalveIt |
- Keep the folder together. The launcher only works from inside it, so move the whole folder rather than dragging the launcher out. Make a shortcut if you want it on your desktop.
- Avoid Downloads and temporary folders. HalveIt stores the tools it downloads, and by default your converted files, inside its own folder.
No administrator rights are needed, and nothing is installed anywhere else. Deleting the folder removes HalveIt completely.
cd ~/Documents
git clone https://github.com/pxspaces/halveit.git HalveIt
Or download the ZIP from the repository page and unpack it into the location above.
| System | What to do |
|---|---|
| Windows | Double-click Start HalveIt.bat |
| macOS | Double-click Start HalveIt.command |
| Linux | Double-click start-halveit.sh, or run ./start-halveit.sh |
If macOS refuses to open it, that is because a browser downloaded it. macOS marks anything a browser fetches and asks before running it once. It does not happen if you cloned this repository or downloaded it from a terminal, only if you used a browser. Try to open it first, so the refusal is recorded, then:
- macOS 15 Sequoia and later: open System Settings, go to Privacy & Security, scroll to the bottom, and press Open Anyway beside the message about HalveIt. Confirm, and it never asks again.
- macOS 14 and earlier: right-click the file, choose Open, then press Open in the warning.
Either way it is once, not every time. A terminal is not affected at all, so
bash "Start HalveIt.command" works whatever macOS thinks.
Missing Python? On Windows HalveIt downloads a private copy, about 12 MB, into its own folder. Nothing outside the HalveIt folder is touched, and deleting the folder removes it completely. On macOS and Linux it names the one command that installs it.
The folder can be moved or renamed afterwards. Nothing inside it records where it lives.
The user guide has these steps in full, with what to do when each one misbehaves.
HalveIt needs ffmpeg, which does the actual conversion. If it is not
already on your computer, press Download and continue, roughly 60 to 75 MB,
saved in the bin folder next to this file.
Prefer to install it yourself? Any of these work, and HalveIt will find it:
winget install Gyan.FFmpeg # Windows
brew install ffmpeg # macOS
sudo apt install ffmpeg # Linux, or your distribution's equivalent
HalveIt opens by asking what you would like to do, and then shows you the settings for that job instead of all of them at once. Make it smaller, fit a size limit, change the format, split it into pieces, cut out the bits you want, remove a section, take the sound out, or save just the sound. Every job is a name you pick rather than a setting you have to know about.
Video into H.265, H.264, AV1 or VP9, with quality levels, exact file size targets, resizing, framerate capping, trimming, HDR conversion, grain reduction and deinterlacing.
Splitting and cutting, for video and audio alike. Into equal pieces, every so often, at times you list, or into pieces that each fit a size. Or keep only the pieces you want, or take a section out of the middle and join what is left. You choose between cutting exactly, which re-encodes and applies your quality settings at the same time, and cutting quickly, which copies and is almost instant.
Audio extracted from video or converted between formats.
Presets cover the things people actually want: WhatsApp and email size limits, short-form video, YouTube and websites. The presets on offer change to suit whatever you selected.
The full inventory is in FEATURES.md.
- Test before you commit. Convert a short sample, or several settings at once, and see the finished size and time before spending minutes on it.
- Compare properly. Wipe between the original and the result frame by frame, play both together, or open either in your own player.
- Size targets are a ceiling, not a quota. A file that already fits is left alone rather than inflated.
- Graphics card acceleration is proven, not assumed. It is offered only after a real test encode succeeds, and its cost is stated: about twice as fast, noticeably larger files.
- Your originals are never touched by default. Deleting them is opt-in, and happens only after the result passes every check.
- It asks once what you work with, then shows you only the settings that matter. Change it any time from the header.
- Updates are checked when you ask, never on startup, and HalveIt can update itself in place. No terminal, no git, nothing to re-download.
halveit open the interface
halveit holiday.mp4 convert one file with the default settings
halveit ~/Videos convert everything in a folder
halveit -p whatsapp clip.mov fit WhatsApp's size limit
halveit --terminal step-by-step questions instead of flags
halveit --list-presets show every preset
halveit --info video.mp4 describe a file without changing it
halveit --dry-run video.mp4 show the command without running it
halveit --split-parts 4 talk.mp4 four equal pieces
halveit --split-every 10:00 lecture.mp4 a new file every ten minutes
halveit --split-at 1:30,4:00 show.mp4 split at those two points
halveit --split-size 16 holiday.mp4 pieces that each fit 16 MB
halveit --cut 0:10-0:20 clip.mp4 keep that piece, drop the rest
halveit --remove 2:00-3:00 talk.mp4 take that out and join what is left
halveit --audio none clip.mp4 the same video with no sound
Run it as python3 -m halveit from inside the folder, or python3 run-halveit.py from anywhere, or use the launcher. --help lists every option.
HalveIt opens your computer's default browser. To use a different one, once:
halveit --browser firefox
Rename presets.example.json to presets.json and edit it. Custom presets
appear alongside the built-in ones, and reusing a built-in key replaces it.
Python with no third-party dependencies, so it runs on whatever Python your system already has. The interface uses one typeface, Inter, bundled into the folder so it looks the same offline.
The interface is a small server bound to 127.0.0.1 that your browser talks to.
It is not reachable from your network, every request must carry a key generated
fresh at startup, and requests arriving under any other hostname are refused.
ffmpeg does the encoding. HalveIt builds the command, runs it, reads its progress, and checks the result.
Nothing is uploaded anywhere. The only network access is downloading ffmpeg.
There is a test suite, which also needs nothing installed:
python3 -m tests everything
python3 -m tests --fast the half that does not need ffmpeg
Some of it builds ffmpeg commands and checks them. The rest converts a generated test picture and measures the result, because a setting that looks right in a command can still ruin the image, and only measuring catches that.
MIT. See LICENSE.
ffmpeg is a separate program under its own licence. HalveIt downloads it at runtime rather than bundling it, and does not modify it.