AppyVibes
Ounce is a simple Mac app that makes video files smaller without making them look noticeably worse.
Drop in one video, hundreds of videos, a folder, folders inside folders, or an entire drive. Choose your format, quality and maximum resolution. Ounce handles the complicated bit.
Why it feels this simple
Ounce was the first app we made, because it was the one we needed ourselves. Every tool we tried got something wrong, so we built one that fixes all of it and then keeps the whole lot out of your way. That is where the complexity went. There are three menus.
Drag in a folder with thousands of files.
Then go and have a break.
You can give Ounce a messy folder containing originals, already compressed videos and files it has seen before. You don’t need to sort it first.
Most of the work Ounce does is work you shouldn’t have to think about. That’s rather the point.
See what it actually does
We started with fourteen videos recorded on an iPhone. Every one was already HEVC, an efficient format, so on paper there should not have been much left to take. Ounce processed the folder on an M1 Pro in under five minutes and recovered 211 MB, with several files ending up close to half their original size. It’s narrated, so turn your sound on.
The recording is sped up through the middle, for the obvious reason that nobody wants to watch five minutes of progress bars. The file sizes and percentages on screen are the real ones. Why already compressed phone video still shrinks this much.
Built for people who just want smaller videos
Bitrates. Codecs. Profiles. Presets. Constant rate factors. Encoding passes. Ounce doesn’t expect you to understand any of that.
There are just three things to choose.
Then drop in your files and let it get on with it.
Compress, convert, or both
Ounce is the tool for the job nobody wants to do by hand: a folder, a library, or a whole external drive of video that is quietly taking up hundreds of gigabytes. It works through all of it, and everything it does is designed so you can set it going without supervising it.
The format going out is chosen separately from whatever came in. Hand it a folder of MOV files and ask for MP4 and that is what comes back. It reads 19 container types, so a mixed archive of old and new footage is one job, not twenty.
By default the compressed copy is written beside the original and nothing is touched. Turn on Replace Originals and Ounce swaps them, but only after confirming the new file is complete, playable and genuinely smaller, and the original then goes to the Trash where you can get it back.
Every file Ounce finishes is marked with the exact settings used. On the next run it recognises those and skips them, so a folder holding a mix of untouched originals, videos you compressed yourself years ago and files Ounce has already done is handled correctly without you separating anything out first.
You never have to remember what you have already compressed. That is the app’s job.
One video, a folder, or your entire archive
Ounce isn’t limited to processing one carefully selected file at a time.
Ounce searches through everything inside and finds the videos for you. So if you’ve accumulated years of footage across hundreds of folders, you don’t need to open every folder and process each file manually.
Real folders are messy. You might have huge original videos mixed with videos you’ve already compressed, videos Ounce has processed before, duplicate folders, and files that are already about as efficient as they’re going to get.
That’s fine. Ounce checks what it finds and avoids unnecessary work. If it has already processed a file using the same settings, it recognises that and skips it. Run Ounce over the same archive again next month and it doesn’t blindly compress everything again.
It checks whether compression is actually worth doing
Some files are already extremely well optimised. Trying to compress one again could take twenty minutes only to produce something larger than the original. Ounce checks first.
Before committing to the full conversion, it tests small sections of the video using the actual settings you’ve selected and estimates whether there is anything useful to gain. If the file is already too efficiently compressed, Ounce leaves it alone. That means less wasted time, less wasted electricity and less pointless encoding.
What Ounce will never do
Even after its initial checks, Ounce checks the result again when the full conversion has finished. If the new file isn’t actually smaller than the original, Ounce doesn’t keep it.
So whichever quality setting you choose, you never finish with a supposedly compressed video that’s larger than the one you started with.
The resolution setting is a maximum, not a target. Choose 4K and give Ounce a 1080p video and it stays 1080p. Choose 1080p and give it a 720p video and it stays 720p.
Upscaling would make the file larger without adding any real detail. There is no point, so Ounce doesn’t do it. Portrait video is handled properly too, with the original proportions preserved.
A conversion reaching 100% doesn’t automatically mean the resulting file is healthy. Ounce doesn’t assume it worked.
It opens the finished file again and verifies that it can actually be read and that the video is complete, rather than simply checking that a file exists. Only then is the conversion considered finished.
Drop in a large drive and there may be more than ordinary video files inside: a Photos library, a Final Cut project, an iMovie library, a Logic or Premiere project. Ounce deliberately avoids reaching inside these and changing their internal files.
Making an app convenient isn’t useful if convenience makes it reckless.
If a folder already contains another file with the name Ounce wants to use, it creates a different filename instead. The existing file stays where it is.
And if the same video appears twice because you dropped in overlapping folders, it isn’t processed over and over. Small details, but important ones when you’re trusting an app with a large archive.
Changed your mind? Press Stop. Ounce stops the active conversion rather than finishing the current video first and merely declining to start the next one.
Any incomplete output is discarded, so you aren’t left with half a video sitting beside the original looking like a finished file.
Your originals aren’t simply deleted
If you turn it on, Ounce explains exactly what will happen before it touches anything.
Once the replacement has passed Ounce’s checks, the original is moved to your Mac’s Trash. It isn’t permanently deleted. So if you change your mind, your original can still be recovered.
Already compressed on an iPhone?
This surprised us too. Modern iPhones already record video using HEVC, also known as H.265. HEVC is an efficient video format, so you might reasonably assume there isn’t much more Ounce could do with it. There often is.
In one of our tests, we gave Ounce a folder containing fourteen iPhone videos that were already HEVC. The folder came back 211 MB smaller, with some individual videos ending up around half their original size while looking effectively the same.
When your iPhone records a video, everything has to happen in real time. The camera can’t ask you to stop moving for thirty seconds while it works out the most efficient way to encode the last scene.
It has to capture, process and save each moment as it happens, while managing battery life, temperature and performance. So it has to make fast, sensible decisions.
Ounce gets the finished video. There is no camera waiting for it. No frame is about to arrive. Nothing is going to be dropped if it takes a little longer to analyse the footage.
That means Ounce can concentrate on compressing efficiently. Simple scenes can use much less data. Detailed or fast moving scenes can keep the data they actually need. The result can be considerably smaller even when the original was already recorded in HEVC.
What to choose, and what it means
But if you want to know what each setting actually does, it is all here. Ounce takes care of the encoder settings underneath. You just choose where the video is going.
Our all round choice
Best for: shrinking an archive you want to keep.
Small, high quality video, and Apple silicon encodes it extremely quickly using dedicated hardware built into the chip. Plays on Apple devices, Windows and Safari. For most people compressing videos for storage, this is where we’d start.
When compatibility matters
Best for: a file you need to be certain will open anywhere.
The most widely supported video format there is. It plays on an enormous range of devices, players and older software, at the cost of a somewhat larger file than HEVC.
Smallest files
Best for: video going onto a website.
Produces the smallest files of the four at a given quality, which is why it suits web delivery. It takes longer to encode because current Apple silicon has no AV1 hardware encoder, so the work is done on the CPU.
Broad browser support
Best for: the web, where older browsers still matter.
Highly efficient and supported by every modern browser, including systems where AV1 may not be the best choice. Like AV1, it is processed in software on current Apple silicon.
Your source video doesn’t need to already be MP4. Ounce reads 19 container types, so you can point it at a mixed archive of old and new footage and it will find the video in all of it.
Because the format going in and the format coming out are chosen separately, Ounce is also a converter. Give it a folder of MOV files and ask for MP4, and that is what you get back.
A 4K video doesn’t always need to stay 4K. If you’re keeping the original footage, perhaps it does. If it’s going onto a website, into social content, or into a presentation where it appears in a much smaller space, those extra pixels are storage and bandwidth nobody sees.
Anything already below your chosen maximum is left exactly as it is. Ounce reduces resolution when you ask it to, and never increases it. Choose 4K, give it a 1080p video, and it stays 1080p.
The cap applies to the shorter side, which is what makes portrait video work properly. A tall clip from a phone keeps its proportions and is never squashed into a landscape shape.
Different jobs have different priorities. Sometimes you need the smallest possible file for a website. Sometimes you’re recovering hundreds of gigabytes from an archive. Sometimes you simply want your videos to take up less room without being able to tell they were touched. That last one is the main reason we built Ounce.
Whichever you choose, quality is held steady across the whole video rather than a fixed data rate being spent evenly. Busy, detailed scenes keep the data they need. Simple ones use far less. And whatever setting you pick, Ounce will not keep a result that came out larger than the original.
Made specifically for Apple silicon
When you’re creating MP4 video using H.264 or HEVC, Ounce uses Apple’s dedicated media engine. That’s specialised hardware inside your Mac whose entire job is encoding and decoding video. The result is very fast compression without hammering the main CPU.
Different Apple silicon Macs have different amounts of processing power, and Ounce accounts for that. It processes multiple videos at once, with the amount of parallel work adjusted according to the chip inside the Mac.
For WebM formats such as AV1 and VP9, where Apple doesn’t currently provide dedicated encoding hardware, Ounce uses the performance cores for the heavy work while keeping resources available so the rest of the computer stays responsive. The point isn’t to make a benchmark look impressive. It’s to use the hardware you’ve paid for intelligently.
We’d rather be clear about this. H.264 and HEVC can use the dedicated video encoding hardware built into Apple silicon, which makes MP4 very fast. AV1 and VP9 encoding currently has to be performed by the CPU, so WebM takes longer. That’s a hardware limitation rather than Ounce artificially slowing anything down.
If you’re compressing a large archive for personal storage, HEVC MP4 is probably the sensible choice. If you’re creating particularly small files for a website, the additional time required for AV1 may be worthwhile.
Nothing leaves your Mac
Ounce doesn’t upload them anywhere. There is no cloud conversion service in the background. The actual encoding happens on your Mac.
Ounce doesn’t even request network permission from macOS. So when we say your videos stay on your Mac, that isn’t simply a privacy policy promise. The app isn’t given the ability to send them anywhere in the first place.
com.apple.security.app-sandbox
com.apple.security.files.user-selected.read-write
com.apple.security.files.bookmarks.app-scope
no network entitlement of any kind
You can use it without an internet connection. You can use it on a plane. Read the full privacy policy.
Another real batch
Eleven clips from a DJI Osmo Pocket 4, recorded in H.265. Like the iPhone footage above, every one of them had already been compressed once by the camera as it recorded. Some individual files still came out more than 60% smaller.
These aren’t theoretical estimates or carefully invented marketing examples. They’re the actual files and numbers Ounce showed during the run.
Six of the eleven, the ones legible in the capture below.
What happens to your originals, whether it touches your Photos library, why it can be run over the same drive twice, which format to pick, and what it does with metadata.
One useful Mac app. One payment.
$9.99Once.
Buy Ounce once and the app is yours. Future Ounce updates are included too. If we ever create other subscription products in the future, that doesn’t change what you’ve already bought.
Download on theMac App StoreApple silicon Mac required. macOS 14 or later.