Free and open source. Runs entirely on your Mac.
A free video compressor for Mac. Up to 97.8% smaller.*
Batch-compress camera footage to HEVC (H.265) on your Mac. Whole folders at once. Two quality choices, no settings to learn, originals never touched.
Results
Compression results on real footage.
Measured on real footage, not a benchmark clip. How we measured
Original vs compressed, side by side.
Your browser can't play HEVC. Download both files below to compare.
The left side is a 100 Mb/s HEVC preview of the original — browsers can't play ProRes. The right side is the actual SkinnyVideo output. Download the real files to check.
SHA-256
a8df15dd22d4c8fab40c804fe9b9ca9fe1341d3b3c46b6dd63a4f6892b920cbeSHA-256
f50237e076369fc1dc5ae21d6c108c612855df384e1cfbb01e4a9bf7c2098062| Resolution | 3840 × 2160 |
|---|---|
| Frame rate | 25 fps · 184 frames |
| Duration | 7.36 s · no audio |
| Color | Rec. 709 SDR |
| Original | ProRes 422 HQ · 10-bit 4:2:2 · 645 Mb/s |
| Output | HEVC Main 10 · 10-bit 4:2:0 · 14.4 Mb/s |
| Size reduction | 97.8% · 593 MB → 13.3 MB |
| PSNR | 49.5 dB |
| SSIM | 0.990 |
| Tier | Slow But Better |
| Make It Fast, same clip | 11.3 MB · PSNR 49.5 dB |
| Encoder settings | SkinnyVideo defaults, zero config |
Measured on an Apple M2 Pro with the bundled FFmpeg; method and script in docs/BENCHMARKS.md.
How it works
Compress whole folders at once.
Drop
A folder or a pile of files, anywhere on the window. Non-video files are ignored, not errors.
Pick a quality
The only decision you make: Make It Fast or Slow But Better.
Make It Fast
Hardware HEVC via Apple VideoToolbox.
Encodes on the media engine in your Mac's chip, so a card dump finishes while you keep editing.
- About 2× real time on 4K Sony footage*
- Often the smaller file
- Mac stays usable
Slow But Better
Software HEVC via x265. Keeps fine detail.
A software encoder that spends several times longer per frame to keep fine detail — grain, texture, gradients — that fast hardware encoding smooths away. File size lands either side of Make It Fast's, and is sometimes larger. On fanless or lower-core Macs such as MacBook Neo it is noticeably slower, but it completes normally.
- Keeps grain, texture and gradients
- Uses more of your Mac while it runs
Start
Walk away. Results land in a new Compressed_<date> folder inside your Output folder, same names, flat.
Safe by default
Originals never touched.
Your videos never leave your Mac.
Sources are read-only.
Never moved, renamed, changed, or deleted.
Results go to a new folder.
Don't like it? Trash the folder. Your masters are where they were.
Keeps the receipts.
What went in, what came out, reclaimed totals per drive.
Lifetime reclaimed 12 TB total · 2 drives
History 50 batches
Nerd Mode
Nerd Mode. CRF, presets, full encoder control.
Full encoder control for people who know exactly what they want. CRF, presets, quality scale, bit depth, dry runs. Set per batch, never left behind for the next user. Built on a self-compiled FFmpeg with x265 and VideoToolbox, nothing else bundled.
- CRF 0-51 Slow But Better
- Constant-quality control for x265. Default 18. Lower is larger and cleaner.
- ultrafast → veryslow preset
- Nine snap positions. Trade encode time for file size. Default medium.
- Quality 1-85 Make It Fast
- VideoToolbox quality scale. Default 62. Capped at 85, where the bitrate curve goes vertical.
- 10-bit → 8-bit
- Appears only when the batch contains a file deeper than 8 bits (10- or 12-bit). 8-bit files are left alone.
- Dry run
- Scan the batch and report the totals. Nothing is written. Check before an overnight job.
- Per batch
- Each batch carries its own settings into the queue. Reset to defaults is one click.
Limits
What it doesn't do.
- Edit, trim, or color anything
- Run on Intel Macs
- Write ProRes, DNx, or AV1
- Watch a folder and compress new files automatically
- Promise "no quality loss". It aims for visually identical.
About
Built by a production manager.
I'm Pritam Malakar, corporate video production manager, and I built SkinnyVideo for my own team. Every tool I tried wanted either a terminal or a dozen decisions before it would touch a single file. Nobody wants to. So: two buttons, no settings, originals untouched.
GPL licensed. Source, releases, and bug tracker are public. No paid tier, no plan for one.
Questions
Questions people ask.
Does it work on Intel Macs?
No. SkinnyVideo runs only on Apple Silicon Macs, including MacBook Neo, on macOS 13 and up.
Does it lose quality?
HEVC is lossy, so yes, technically. Both tiers aim to look visually identical to the source. Slow But Better spends several times longer per frame to keep fine detail — grain, texture, gradients — that fast hardware encoding smooths away; its file is not necessarily smaller than Make It Fast's.
Does it upload my videos anywhere?
No. Compression runs entirely on your Mac and your videos never leave it. The app's only internet use is an optional check for new versions on GitHub, which you can turn off.
Is it safe to install?
Yes. It's signed and notarized by Apple, open source under GPL-2.0-or-later, and every release publishes a SHA-256 checksum.
Where do the compressed files go?
Into the Output folder you pick. Each run creates a new Compressed_<date> folder inside it, flat. The originals are never opened for writing, moved, or deleted.
Can it compress ProRes?
Yes. A 593 MB ProRes 422 HQ master came out at 13.3 MB (97.8% smaller) with Slow But Better.
Can it compress iPhone video that's already HEVC?
Yes, but the gain varies a lot: anywhere from about 17% to 85% depending on the clip, so there is no single number for phone video. The big savings come from camera codecs — XAVC, Canon H.264, ProRes — not from phone HEVC.
How is it different from HandBrake?
HandBrake is a full manual transcoder with hundreds of settings. SkinnyVideo is folder-first with two choices, and Nerd Mode when you want the settings back.
How it behaves
What files can it read?
Files ending in .mp4, .mov, .m4v, .mkv, .avi, .mts, .m2ts, .mpg, .mpeg, .wmv, .flv, .webm, .mxf, .prores, .dnxhd, .avchd, .3gp, .3g2, .ts, .vob or .ogv (upper or lower case) that contain a video stream. Drop a folder or files anywhere on the window; other files in the drop are ignored. In a folder you add (dropped or picked), SkinnyVideo's own output is left out: anything inside a Compressed_YYYY-MM-DD_HHMM run folder, and unfinished files it has recorded; the staging line says how many. Any other file is checked like the rest, even one named like holiday.tmp.mp4. Files you add one by one are always honoured.
Does it keep every audio track?
Yes. Every audio track is kept, in its original order and with its own channel count; tracks are never mixed together. AAC, ALAC, AC-3 and E-AC-3 tracks are copied unchanged. Any other audio, such as PCM, FLAC, Opus, MP3 or DTS, is converted to AAC at 320 kb/s per track. A track the app can’t read is left out, and the file’s row shows a NOTE. Subtitle and data tracks are not kept. The source’s start timecode is carried to the output.
What happens when a file fails?
If the encoder rejects a color tag, the file is encoded again on the same encoder without color tags. If it still fails, SkinnyVideo tries libx265 at CRF 22. Only then is it marked failed, and a copy of the original goes into _FAILED/ inside the run folder. The original in place is never touched.
What does “Duplicate” mean?
You ran the same file into the same Output folder again within the same minute, without quitting in between, so it was already in a batch going to that same run folder. The finished copy was kept and the row says Duplicate (tooltip: “Already in a batch going to this same run folder”). Any other rerun makes a new copy in a new run folder.
Does it keep HDR?
PQ and HLG transfer tags, BT.2020 color tags, and HDR10 mastering display and content light level values are carried to the output. Dolby Vision is not kept: its configuration record is dropped in both tiers, so the output is not marked as Dolby Vision. Make It Fast leaves the per-frame Dolby Vision data in the video stream; Slow But Better removes it. Dolby Vision files get a “Dolby Vision” chip on their row that says exactly what was dropped; HDR10 files get no chip, because nothing is dropped.
Does it keep 10-bit, 12-bit and transparency?
10-bit sources stay 10-bit (HEVC Main 10) unless you turn on 10-bit to 8-bit in Nerd Mode. Sources deeper than 10 bits, such as 12-bit ProRes 4444, come out 10-bit. Alpha channels are not kept: both tiers drop the transparency on purpose and still compress the file, and the file’s row shows a NOTE.
Can I change the order of the queue?
Yes. Drag a queued batch to change the order, before Start or during a run. The next batch to start is always the one shown next; a batch that has started stays where it is.
When do Nerd Mode settings take effect?
They freeze when you click Add batch. Changing them afterwards affects only batches you add later.
Does it remember my Output folder?
Yes. The next launch starts with the Output folder you last chose, as long as it still exists and you can write to it. Otherwise Output starts empty and you pick one.
What warnings can it show?
On launch, if an earlier run was interrupted, it checks the .tmp.mp4 files it left. A leftover can be kept if it is as long as its original and was recorded by this version with its run folder still present: you can keep it under its normal name, at the top of its run folder, or delete it. The rest it offers to delete, and the prompt says why: the file is incomplete, it was recorded by an older version of SkinnyVideo, or its run folder is missing. Nothing else is touched. Before a run, it warns if the output drive has less free space than the videos add up to. If you quit while a finished file is still being written to disk, it asks you to wait.
Are sizes in MB or MiB?
Decimal: 1 MB is 1,000,000 bytes, the same as Finder.
Is Slow But Better always the smaller file?
No, and it doesn't always score higher either. Against Make It Fast it scored higher PSNR on 6 of the 11 clips we measured, within 0.1 dB on 3 (including both ProRes HQ masters), and lower on the two iPhone 4K60 4:2:2 clips. On already-compressed phone footage it can come out larger than Make It Fast: iPhone 12 SDR, 2.0 MB vs 4.6 MB (+3.0 dB). Sony 4K 4:2:0 is another case: 6.3 MB vs 24.4 MB (+2.3 dB).
Download
Get the space back. Free, for Apple Silicon Macs.
Like any other Mac app. Open the .dmg, drag to Applications, launch. Signed and notarized by Apple: no warnings, no workarounds.
* Sony XAVC 4K: 92–97% with Make It Fast defaults: 10-bit 4:2:2 clip 67 MB → 2.1 MB (96.8%), 4:2:0 clip 134 MB → 6.3 MB (95.3%), 62 s 10-bit 4:2:2 clip 1.21 GB → 94.7 MB (92.2%).
* ProRes: the ProRes 422 HQ demo master below, 593 MB → 13.3 MB (97.8%), Slow But Better defaults.
* Already HEVC: anywhere from about 17% to 85% depending on the clip; there is no single number for phone video. Make It Fast / Slow But Better: iPhone 12 SDR 68% / 24%, iPhone 12 HLG 26% / 44%, iPhone 4K60 4:2:2 clip 75% / 85%, a second iPhone 4K60 4:2:2 clip 17% / 47%. The big savings come from camera codecs — XAVC, Canon H.264, ProRes — not from phone HEVC.
* Speed: on an Apple M2 Pro, 4K 25p Sony XAVC encodes at about 2× real time in Make It Fast; 4K60 4:2:2 phone footage runs just under real time. Slow But Better is several times slower than real time on 4K. Speed scales with your chip.
Savings depend on how much your footage moves and how hard the camera compressed it. The app reports the real figure after every batch.