Video Compressor
Shrink a video to a target file size — 10 MB for Discord, 25 MB for email, or any size you pick.
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How Targeting a File Size Works
File size in video is not a setting you can simply request — it is the result of a bitrate multiplied by a duration. To hit a target, the tool works the arithmetic backwards: take the size you want in bits, divide by the length of the clip in seconds, subtract what the audio track needs, and the remainder is the video bitrate.
A 10 MB target on a 60-second clip works out to roughly 1,270 kbps of total data, leaving about 1,140 kbps for the picture after 128 kbps goes to audio. On a 10-minute clip the same 10 MB target leaves only about 100 kbps, which will look rough. Duration is the dominant factor— if the result looks bad, the clip is too long for the target, and trimming it will help far more than any encoder setting.
The tool aims slightly under the target to leave room for container overhead and encoder variance, so results usually land a few percent below the number you asked for rather than a few percent over.
The Presets, and Where the Numbers Come From
- Discord free — 10 MB. The upload ceiling on a free Discord account. Nitro subscribers get considerably more, but 10 MB is what most people are fighting with.
- WhatsApp — 16 MB. The long-standing limit for video sent through WhatsApp. Larger files get re-compressed by WhatsApp itself, usually with worse results than compressing deliberately.
- Email attachment — 25 MB. Gmail’s attachment limit, and the de-facto standard most other providers land near. Anything larger gets pushed into a cloud link.
- Custom. For upload forms with their own limits — job applications, school portals, marketplace listings.
Platform limits change over time and vary by plan, so treat these as good defaults rather than guarantees. If an upload is rejected, drop the target a couple of megabytes and try again.
Getting a Better-Looking Result
- Trim first. Halving the length doubles the bitrate available to every remaining frame. This is by far the biggest lever.
- Consider what is in the frame. A static talking head compresses beautifully at low bitrates. Confetti, rain, fast panning, and grain do not — those need several times the data for the same perceived quality.
- Do not compress twice. Re-compressing an already-compressed file compounds the damage. Always start from the highest quality source you have.
- 1080p is not always right. If the target bitrate is very low, the same file at 720p will look better than a starved 1080p encode, because each pixel gets more data.
How to Use
- Pick a target size, or type your own.
- Drag in the video. It stays on your computer.
- Click Compress. The tool reads the clip length, calculates the bitrate, and shows what it is aiming for.
- Check the reported output size, then download.
Technical notes
- Codec: H.264 with average bitrate targeting, plus a rate cap and buffer to keep spikes in check
- Audio: AAC at 128 kbps, subtracted from the budget before the video bitrate is calculated
- Single pass: two-pass encoding would hit the target more precisely but takes twice as long in a browser, which is a bad trade here
- Resolution: unchanged, apart from rounding odd dimensions down to even
- Fallback: if the clip length cannot be read, the tool switches to quality-based compression (CRF 28) and says so
FAQ
The output is not exactly the size I asked for.
Expected. Bitrate targeting is a prediction, not a hard cap, because the encoder cannot know in advance how compressible each scene is. The tool deliberately aims a few percent under so results land below your limit rather than above it.
The video looks blurry and blocky now.
The target was too small for the clip length. A 10-minute video squeezed into 10 MB has roughly the bitrate of a 2005 web video. Trim the clip, raise the target, or accept the trade — there is no encoder setting that creates data out of nothing.
Why not just let Discord or WhatsApp compress it?
They will, and their settings are tuned for their servers rather than your footage. Compressing deliberately means you choose the trade-off, and you can check the result before it goes out.
Can I make the file smaller without losing quality?
Not meaningfully. Video is already compressed with lossy codecs, so shrinking it further means discarding more picture information. The only lossless savings come from removing things — trimming length, dropping audio, or cutting resolution.
Why is the output always MP4?
Because it is the format every upload target accepts. Compressing into a format the destination then rejects would defeat the purpose.
How long does it take?
Roughly 1–3 minutes per minute of 1080p footage, since the entire video has to be re-encoded on your own CPU. Keep the tab in the foreground — browsers throttle background tabs heavily.
⚠️ Reference Only
Output is generated based on your input and is provided for reference. Results may vary depending on your specific use case, edge cases, or environment-specific behavior. We do not guarantee accuracy of conversions, validations, or computed values.
Always verify critical outputs against official documentation or production environments. We are not responsible for any decisions or losses based on these tool results.