Mac
On Mac: export a smaller copy with QuickTime Player
- Open the video in QuickTime Player.
- Choose File > Export As and pick 1080p, 720p or 480p.
- Save the copy. Lower resolutions give smaller files, but you can't choose an exact size.
Compress a video
Shrink MP4, MOV, WebM or MKV videos to the size you choose, encoded on your own device. Nothing is uploaded, and there’s no account, watermark or limit.
- 1. Drop files
- 2. Adjust
- 3. Download
- No upload. Processing happens on your device.
- No limits. As many files as you like, free.
- No watermark. Your files stay exactly yours.
How to compress a video with filetidy
- 1
Add one or more videos (MP4, MOV, WebM or MKV) by dropping them on the page or tapping to choose them. Each file shows its length, resolution and an estimated output size.
- 2
Under “Target size”, pick a preset such as “Half the size”, or choose “Custom size” and type the number of megabytes you need.
- 3
Leave “Max resolution” on Auto, or cap it at 1080p, 720p or 480p. Tick “Remove audio” if the clip doesn't need sound.
- 4
Press “Compress”, watch the progress and time left, then use Download (or “Download all (.zip)”) to save the MP4 files.
How video compression works
A video file's size is almost exactly its bitrate multiplied by its length. A one-minute clip at 8 megabits per second takes about 60 MB, whatever the content. To hit a size, you therefore choose a bitrate: filetidy divides your target by the duration, keeps a small share for audio and the MP4 index, and gives the rest to the picture.
Phones record at high bitrates because they don't know what you'll do with the footage. A 4K phone clip can use several tens of megabits per second, far more than a phone screen or a chat window needs. Re-encoding at a lower bitrate, and often a lower resolution, removes detail you would rarely notice.
The output is MP4 with H.264 video and AAC audio, the combination that plays on virtually every phone, computer, browser, smart TV and messaging app. Encoding uses your browser's built-in video encoder (often hardware-accelerated), so on a recent device a clip often compresses faster than it plays.
Location tags and other metadata that cameras write into videos are not copied to the compressed file.
- Size formula
- Bitrate (Mbit/s) × duration (s) ÷ 8 = megabytes
- Output
- MP4 (H.264 video, AAC audio), fast-start for instant playback
- Inputs
- MP4, MOV, M4V, WebM and MKV
- Resolution choices
- Auto, 1080p, 720p or 480p; never upscaled
- Typical good-looking bitrates
- About 4–6 Mbit/s for 1080p, 2–3 for 720p, 1 for 480p at 30 fps
- Processing
- On your device, in a background Web Worker
Other ways to do it
Windows
On Windows 11: export at a lower quality with Clipchamp
- Open Clipchamp (included with Windows 11) and create a new video.
- Import your clip and drag it onto the timeline.
- Click Export and choose 480p or 720p instead of 1080p.
Clipchamp asks you to sign in with a Microsoft account, and the export size depends on the clip; there is no size target.
iPhone & iPad
On iPhone: record smaller videos from the start
- Open Settings > Camera > Record Video.
- Choose 1080p HD at 30 fps or 720p HD at 30 fps instead of 4K or 60 fps.
- In Settings > Camera > Formats, “Most Compatible” records H.264, which other devices play more easily, though files are larger than with “High Efficiency”.
Android
On Android: lower the camera's video size
- Open the Camera app and switch to Video mode.
- Open the camera settings (often a gear icon) and look for video size or resolution.
- Pick FHD 1080p or HD 720p, and 30 fps if a frame rate option exists.
Menu names differ between phone brands. This only affects new recordings; use the tool above for videos you already have.
Lower bitrate or lower resolution?
Both make files smaller, and they work together. Squeezing a 1080p picture into a tiny bitrate produces blocky, smeared motion; the same bitrate spent on 720p looks cleaner because there are fewer pixels to describe. That is why the Auto setting steps the resolution down when the target size is tight.
For screen recordings, slides and tutorials, keep the resolution as high as possible so text stays readable, and cut audio if there's no narration. For phone footage of people and places, 720p is usually indistinguishable from 1080p on a phone screen.
Length matters more than anything: halving the duration halves the size at the same quality. If the estimate shows a warning that the target is too small, trimming the clip will look far better than forcing the bitrate down.
Compression can't be undone. Keep your original and share the compressed copy.
Frequently asked questions
Is my video uploaded anywhere?
No. The video is read from your disk by your browser, decoded and re-encoded on your device, and saved back to it. filetidy never receives the file. You can even disconnect from the internet after the page has loaded.
How accurate is the estimated size?
The estimate is calculated from the video's duration and the bitrate we'll use, and the encoder usually lands within a few percent of it. When you pick a fixed size and the first result still comes out larger, filetidy automatically runs a second pass at a lower bitrate so the file fits.
Will compressing reduce quality?
Yes, some, because detail is discarded to save space. How much you notice depends on the target: “Best quality (−30%)” is hard to tell apart from the original on a phone, while “Smallest (−70%)” is meant for quick sharing. Fast motion and grainy low-light footage suffer first.
Can I compress a 4K or 60 fps video?
Yes. Auto never outputs more than 1080p, which already saves a lot, and when the bitrate is tight it also drops 60 fps footage to 30 fps so each frame gets enough data. Very long 4K files need a lot of memory; if your device runs out, pick 720p or compress a shorter section.
My iPhone video says the codec isn't supported. Why?
Recent iPhones record in HEVC (H.265). Safari, and Chrome or Edge on most recent computers, can decode it. Some browsers and older systems can't, in which case filetidy switches to a slower compatibility encoder, and if that also fails it tells you which browser to use.
Why does the page download an extra file sometimes?
If your browser lacks a built-in H.264 encoder or can't decode your video, filetidy downloads a one-time 32 MB compatibility encoder (ffmpeg compiled to WebAssembly). It is the program that's downloaded, not your video being uploaded, and your browser caches it for next time.
Is there a limit on file size or number of videos?
There is no fixed limit. Videos are processed one at a time to keep memory use in check; very long or very high-resolution files may fail on phones with little memory, and the error will say so for that file only.
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Last updated October 28, 2026