Why does compressing a video take so much longer than an image?

Compression re-encodes every single frame of the video, the most processing-intensive thing any video tool here does. Medium/Strong and Custom Target all run two full encoding passes to hit their target reliably, so expect real processing time, especially for longer or higher-resolution videos.

Why does my phone video fail to process right away?

Some phone-recorded videos, particularly .mov files, use a codec this tool can't read. If processing fails immediately, try re-exporting the video from your phone's own share options first, which often converts it to a more widely-compatible format.

Why is the result not exactly 25 or 50 percent smaller?

Those buttons aim the encoder at a size computed from your original, then adjust once if it lands over. The result is meant to be at or under the target, and the page prints the real percentage, so a result a little smaller than the label is normal.

Will compressing lower the picture quality?

Yes, to some degree. The video is re-encoded, so detail is traded for size, and Strong or a small Custom Target costs more than Light. Choosing Lower resolution to 720p reduces sharpness on large screens but helps reach small targets.

What does the Manual Quality slider control?

The Compression amount maps to a constant-quality setting, where higher percentages mean heavier compression and a longer wait. The tool also caps the bitrate near 90 percent of the source's, so an already efficient file is less likely to grow.

Why did it say the target was not reached?

The encoder could not get below your size at the chosen settings. The page shows how small it got. Try Strong, a larger target, a shorter source, or tick Lower resolution to 720p, which removes pixels and so helps most.

I dropped a MOV or MKV file. What format do I get back?

Always MP4. The result is H.264 video with AAC audio, saved as compressed_ followed by the original name with an .mp4 ending. That format plays on nearly every phone, browser and chat app.

How do I compress a video to 25 MB?

Drop the video, choose Custom Target and press 25 MB (email) or type 25 in the Target size box, then press Compress Video. The page encodes toward that size and checks the real file, and repeats up to twice if it came out over. There are also 8 MB, 16 MB (WhatsApp), 50 MB and 100 MB shortcuts.

Will the file always be under my target?

It is counted as reached only when it is at or under your size. If a very long or detailed video cannot get that small, the page says it missed and shows how small it got. Then tick Lower resolution to 720p, trim the video or pick a larger target.

Can I cut part of the video out first?

Yes, in Custom Target mode. Fill in Trim start and Trim end as seconds or m:ss, such as 0:30 and 2:15. Only that part is kept, and the target size is for that part. Because size is bitrate times length, a shorter clip keeps more quality at the same size.

Is my video uploaded?

No. The video is compressed by an engine running in your browser, so the file never leaves your device. The engine itself, about 25 MB, is downloaded once before the first video job.

Home/Video Tools/Compress Video

Compress Video

Reduce video file size for sharing

Files never storedRuns on your device

Your files are processed on your device. The first use downloads a processing engine, which your browser then keeps.

Drop a video to compressTap to choose a video to compress

or click to browseor tap to choose

Reduce video file size

Large files (over 200 MB) may take longer or run out of browser memory

About Compress Video

Reduces a video file's size, typically to fit an upload limit or speed up sharing, by re-encoding it at a lower quality level. Medium/Strong aim for at least a 25%/50% smaller file using the same size-targeting encode as Custom Target, instead of a vague quality label. Some videos are already compressed so well that they cannot be made smaller; the tool tells you and offers your original back. "Manual Quality" gives direct slider control if you'd rather not use a percentage target. Runs entirely in your browser — the video never leaves your device.

Watch: Compress Video in Action

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Why does compressing a video take so much longer than an image?: Compression re-encodes every single frame of the video, the most processing-intensive thing any video tool here does. Medium/Strong and Custom Target all run two full encoding passes to hit their target reliably, so expect real processing time, especially for longer or higher-resolution videos.
Why does my phone video fail to process right away?: Some phone-recorded videos, particularly .mov files, use a codec this tool can't read. If processing fails immediately, try re-exporting the video from your phone's own share options first, which often converts it to a more widely-compatible format.
Why is the result not exactly 25 or 50 percent smaller?: Those buttons aim the encoder at a size computed from your original, then adjust once if it lands over. The result is meant to be at or under the target, and the page prints the real percentage, so a result a little smaller than the label is normal.
Will compressing lower the picture quality?: Yes, to some degree. The video is re-encoded, so detail is traded for size, and Strong or a small Custom Target costs more than Light. Choosing Lower resolution to 720p reduces sharpness on large screens but helps reach small targets.
What does the Manual Quality slider control?: The Compression amount maps to a constant-quality setting, where higher percentages mean heavier compression and a longer wait. The tool also caps the bitrate near 90 percent of the source's, so an already efficient file is less likely to grow.
Why did it say the target was not reached?: The encoder could not get below your size at the chosen settings. The page shows how small it got. Try Strong, a larger target, a shorter source, or tick Lower resolution to 720p, which removes pixels and so helps most.
I dropped a MOV or MKV file. What format do I get back?: Always MP4. The result is H.264 video with AAC audio, saved as compressed_ followed by the original name with an .mp4 ending. That format plays on nearly every phone, browser and chat app.
How do I compress a video to 25 MB?: Drop the video, choose Custom Target and press 25 MB (email) or type 25 in the Target size box, then press Compress Video. The page encodes toward that size and checks the real file, and repeats up to twice if it came out over. There are also 8 MB, 16 MB (WhatsApp), 50 MB and 100 MB shortcuts.
Will the file always be under my target?: It is counted as reached only when it is at or under your size. If a very long or detailed video cannot get that small, the page says it missed and shows how small it got. Then tick Lower resolution to 720p, trim the video or pick a larger target.
Can I cut part of the video out first?: Yes, in Custom Target mode. Fill in Trim start and Trim end as seconds or m:ss, such as 0:30 and 2:15. Only that part is kept, and the target size is for that part. Because size is bitrate times length, a shorter clip keeps more quality at the same size.
Is my video uploaded?: No. The video is compressed by an engine running in your browser, so the file never leaves your device. The engine itself, about 25 MB, is downloaded once before the first video job.

How to use Compress Video

Drop a video, such as MP4, MOV, WebM or MKV. The card shows its name and original size. Choose how to shrink it with the buttons. Medium (25% smaller) and Strong (50% smaller) aim at a size relative to your original. Manual Quality, which is selected when the tool opens, offers a Compression amount slider from 0 to 100 percent in steps of 5. Custom Target takes a Target size in MB, with shortcuts for 8 MB (Discord), 16 MB (WhatsApp), 25 MB (email), 50 MB and 100 MB, and optional Trim start and Trim end boxes to keep only part of the video.

In every mode except Manual Quality you can tick Lower resolution to 720p. Press Compress Video; the status line reports progress and a time estimate. The result shows beside the original, with both players, and downloads as compressed_ plus the original name in MP4.

When to use it

Use it when an email, chat app or upload form refuses a video for being too large, when a screen recording needs to cross a slow connection, or when phone clips are taking up storage you want back. Custom Target suits a hard cap such as 25 MB, while the percentage buttons suit a request to make it noticeably smaller without choosing a number.

When not to use it

Skip it if the video is already small or heavily compressed, because re-encoding may leave it almost the same size or larger; in Manual Quality the page then tells you to keep your original. It is also a poor fit for a very long, high-resolution film on a modest phone or tablet, where the wait can be long. For sound only, use an audio tool.

Tips for best results

Ticking Lower resolution to 720p is the most effective way to reach an aggressive target, since fewer pixels need fewer bits, and the option is labelled much faster as well. Aim a little under the real cap you face, because a result that just misses is flagged as not reached. If Strong reports a missed target, rerun with 720p ticked rather than asking for a tiny file at full resolution. Watch the output before deleting the original.

Limitations

Output is always H.264 video with AAC audio in an MP4 file. A requested size is a target and not a promise: when it is missed, the page says so and keeps the smallest result it reached. Encoding runs on your own device, so time grows with length and resolution, and the first use downloads the video engine. Some phone .mov codecs cannot be read by the engine.

Privacy

Compression happens inside your browser tab with an ffmpeg engine compiled to WebAssembly. Your video is read into memory on your device, and the compressed MP4 is assembled there and handed to you through the Download button. Only the engine's own files come from a public content network on first use; your video is not part of any request.