What is CompressO?
CompressO is a free, open-source app for shrinking video and image files without sending them anywhere. Everything runs locally: the app is a Tauri shell around FFmpeg, pngquant, jpegoptim and gifski, which it calls through binaries that ship inside the bundle, and it makes no network requests except its own update check. Version 3.0 added image compression and conversion alongside the video features, so it now handles JPEG, PNG, WebP and GIF as well as MP4, MOV and AVI, plus rasterising SVG. Batch compression, trimming, subtitle embedding and metadata editing are built in. The macOS build ships as separate Apple Silicon and Intel disk images and is not notarized, so a manual install needs one Gatekeeper command before the app will open.
Verified product facts
- Type
- media converterEditorially reviewed
- Platform
- macOS
- Apple Silicon
- Yes
- Pricing
- Open sourceDeveloper-stated
- Open source
- Yes
- Developer
- Code For RealDeveloper-stated
- Relationship to Nuanyue
- Third-party product — not published by NuanyueEditorially reviewed
- Licence
- AGPL-3.0
- Current version
- 3.0.0Developer-stated
- Official website
- compresso.codeforreal.com/
Last updated . Facts marked developer-stated come from the developer and are not independently confirmed; editorially reviewed marks a Nuanyue judgement.
Key features
What CompressO does at a glance.
Compresses video
With FFmpeg and images with pngquant, jpegoptim and gifski, all through binaries that ship inside the app
Batch compression
For several videos or images at once, including dropping whole folders onto the window
Trims, splits, crops, rotates, flips and rescales video before compressing it
Converts between JPEG, PNG, WebP and GIF, and rasterises SVG to PNG, JPEG or WebP
Builds animated GIFs
From video and recompresses existing GIFs with quality and frame-rate controls
Shows a before-and-after comparison slider
For the original and the compressed file
Embeds subtitles
Into the output video and extracts embedded subtitles as SRT or VTT
Edits title, artist, album, year, genre and copyright metadata, and can preserve EXIF data when compressing images
Runs entirely offline
The developer states the only network request the app makes is its own update check
What you can use CompressO for
- Shrinking screen recordings and phone video before sending them to someone
- Reducing a folder of images to a web-friendly size in one pass
- Trimming and re-encoding a clip without opening a full video editor
- Converting a batch of screenshots to WebP for a website
- Compressing a video without uploading it to an online service
Who is CompressO for?
- People who want a compressor that never uploads their files
- Anyone who prefers an open-source app they can read and build
- Users who need image and video compression in one tool rather than two
Who is CompressO not for?
- Anyone who wants a notarized app with no Gatekeeper prompt — the disk image is unsigned
- Users who need fine codec and preset control, where HandBrake exposes far more
- People on macOS 12 or earlier, since the developer's own Homebrew cask sets the floor at macOS 13
Compatibility
Supported formats: MP4, MOV, AVI, WebM, JPEG, PNG, WebP, GIF, SVG
Limitations
- The macOS build is not notarized, so a manual download is blocked on first launch until you run `xattr -cr /Applications/CompressO.app`; the Homebrew cask does this for you
- The product website states the licence is MIT, while the repository ships an AGPL-3.0 LICENSE file and its README says AGPL 3.0. Nuanyue records AGPL-3.0
- Apple Silicon and Intel Macs need different disk images; there is no single universal build
- Neither the repository nor the product site states a minimum macOS version. The developer's Homebrew cask sets it at macOS 13 Ventura
- The developer reports the Linux build does not start on Debian 13 and Ubuntu 24; the macOS build is unaffected
Strengths and trade-offs
What CompressO does well, and what to weigh before choosing it. Points marked developer-stated come from the developer’s own material and have not been independently confirmed.
Strengths
- Free and open source under AGPL-3.0, with no paid tier, account, watermark or file-size limit.
- Compression happens entirely on the Mac; the developer states the only network request the app makes is its own update check.Developer-stated
- Handles images and video in one app, including format conversion, GIF creation and SVG rasterisation.
- Ships separate Apple Silicon and Intel disk images, so neither kind of Mac runs the app under translation.
- Batch processing, trimming, subtitle embedding and metadata editing are all in the app rather than in separate tools.
Trade-offs
- The macOS build is not notarized, so Gatekeeper blocks a manual install until the quarantine attribute is removed.Developer-stated
- The website and the repository disagree about the licence: the site says MIT, the repository ships AGPL-3.0.
- There is no universal macOS build, so you have to know which chip your Mac has before downloading.
- No minimum macOS version is published anywhere first-party, so the floor can only be inferred from the Homebrew cask.
First-use experience
What the app asks of you when you set it up. Only established facts appear here; anything we could not confirm is left out rather than guessed at.
- Installation
- Install with `brew install --cask codeforreal1/tap/compresso`, or download the disk image for your chip — `CompressO_3.0.0_aarch64.dmg` for Apple Silicon, `CompressO_3.0.0_x64.dmg` for Intel — open it and drag the app into Applications.
- First launch Developer-stated
- A manual install is stopped by Gatekeeper with the message that CompressO is damaged and should be moved to the trash. The developer's fix is to run `xattr -cr /Applications/CompressO.app` in Terminal; the Homebrew cask runs that command for you, so the app opens normally from a brew install.
- System integration Developer-stated
- The developer's feature list includes an Open with CompressO entry in the file manager's context menu, and the macOS dock icon shows a percentage while a job is processing.
- Apple Silicon
- Supported
What it does
CompressO takes a video or an image and makes it smaller. It is a Tauri application — a Rust shell with a React interface — that drives FFmpeg for video and pngquant, jpegoptim and gifski for images, using binaries that ship inside the bundle rather than anything installed on the system. Nothing is uploaded: the developer states the app works completely offline and the only network request it makes is its own update check.
Version 3.0 is the release that turned it from a video tool into a media tool. Image compression, image transformations, SVG rasterisation, GIF creation and GIF recompression all arrived in that version, along with a before-and-after comparison slider for checking the output against the original.
What you can do to a file
Beyond compressing, the app will trim and split video, crop, rotate, flip and rescale it, convert between JPEG, PNG, WebP and GIF, rasterise an SVG, embed a subtitle track into a video, pull an embedded subtitle track back out as SRT or VTT, and edit the title, artist, album, year and genre fields. Batch mode applies one set of settings across several files, and folders can be dropped onto the window rather than selected file by file.
That is a wider feature set than a simple compressor, but a narrower one than a video editor: there is no timeline, no multi-track compositing and no codec control beyond choosing the codec and the quality. HandBrake remains the tool for anyone who wants to reason about encoding settings.
Installing it on a Mac
There are two routes. Homebrew, with
brew install --cask codeforreal1/tap/compresso, or a manual download from the
releases page — CompressO_3.0.0_aarch64.dmg for Apple Silicon and
CompressO_3.0.0_x64.dmg for Intel. There is no universal build.
The manual route runs into Gatekeeper, because the disk image is not notarized.
macOS reports that the app is damaged and should be moved to the trash, which is
misleading — the developer’s own instructions are to run
xattr -cr /Applications/CompressO.app and launch it again. The Homebrew cask
does this automatically, which is the reason to prefer it. Notarization is
deliberately skipped: the developer’s note in the README explains that paying
Apple’s annual fee for a free app is not something they are willing to do.
Neither the repository nor the product site publishes a minimum macOS version. The developer’s own Homebrew cask sets it at macOS 13 Ventura, which is the only first-party figure available.
Licence
The repository ships the AGPL 3.0 text as its LICENSE file and the README states the project is licensed under AGPL 3.0. The product website’s footer says something different — MIT License, use it anywhere. The repository is the operative source: the code is AGPL-3.0. Anyone intending to embed CompressO in another product should read the licence rather than the marketing page, because the two are not the same.
Release history
Dated releases recorded for CompressO, newest first, each with the source it was read from.
3.0.0
Adds image compression for JPEG, PNG, WebP and GIF, image transformations, SVG conversion, video-to-GIF and GIF compression, an in-app updater and a before-and-after comparison slider.
Source: Source repository
2.1.1
Fixes durations over an hour being formatted without the hour component, and tidies the settings labels and About window.
Source: Source repository
2.1.0
Adds subtitle upload and extraction, a customisable theme colour, audio amplification up to 200% and frame capture from the video player.
Source: Source repository
Questions about CompressO
Is CompressO free?
Yes. It is free and open source under the GNU Affero General Public License v3.0, with no paid tier, no account and no watermark.
Does CompressO upload my files?
No. The developer states the app works completely offline and makes no network requests other than its own update check. Compression is done by binaries bundled inside the app.Developer-stated
Why does macOS say CompressO is damaged?
Because the disk image is not notarized. The developer's own instructions are to run `xattr -cr /Applications/CompressO.app` in Terminal, or to install through Homebrew, whose cask removes the quarantine attribute automatically.Developer-stated
Which macOS version does CompressO need?
Neither the repository nor the product website states a requirement. The developer's Homebrew cask sets the floor at macOS 13 Ventura.
Does CompressO run natively on Apple Silicon?
Yes. The release publishes a separate aarch64 disk image for Apple Silicon Macs alongside an x64 image for Intel Macs.
What licence is CompressO under?
AGPL-3.0. The repository's LICENSE file is the AGPL 3.0 text and the README states AGPL 3.0, although the product website's footer claims the app is MIT licensed.
Competitors
Direct competitors: overlapping features aimed at the same users.
ImageOptim
Compress images and remove EXIF information.
Both compress images locally, but ImageOptim is lossless-first and open source under the GPL, while CompressO also handles video and is licensed AGPL-3.0.
JPEGmini
Patented JPEG recompressor for Mac, free for 50 images a day.
Both shrink image files on macOS, but JPEGmini is a closed-source commercial product with a free daily quota while CompressO is free and open source.
Similar apps
Related in purpose, but not a straight swap.
HandBrake
Video transcoder for converting media to modern formats.
Both shrink video files, but CompressO is a lightweight image-and-video compressor while HandBrake is a full transcoder with codec and preset control.
PDF JustFit
Compress, convert and question PDFs on iPhone and iPad — all on-device.
Both reduce file size locally, but CompressO targets video and images on macOS while PDF JustFit targets PDFs on iOS.
Links
Sources
Facts on this page are checked against the sources below. Last updated .
