Compress Video to MP4
Re-encode video as MP4 with a chosen width limit and H.264 quality level. Keep or remove audio and compare the actual source and output sizes.
- 01Add your video
- 02Adjust & preview
- 03Export your result
Video workspace FFmpeg-powered
Video stays on your device. The editing engine downloads from a CDN when first used.
Preview uses browser-supported codecs. The FFmpeg engine may accept additional file types.
Export settings
Choose a video to begin.
FFmpeg diagnostics and export command
If export fails, copy these details. The last stderr messages usually explain the cause. Do not paste private filenames if sensitive.
Logs will appear when export starts.
When to use this tool
Prepare a smaller recording for an attachment or upload limit by reducing resolution or encoding quality. Compare the downloaded file with the original because an already efficient source can become larger.
How to use Compress Video to MP4
- Select a video to inspect its source preview and duration.
- Choose an output width and compression level, and decide whether to keep audio.
- Export MP4, compare the reported file sizes, and check fine details and sound before sharing.
Supported video formats and output
Accepts supported video containers such as MP4, MOV, WebM, MKV, AVI and M4V. Output is H.264 MP4 with optional AAC audio. The width setting requests a horizontal dimension, not a frame height or guaranteed size reduction. Smaller sources can be enlarged.
Reduce a recording while keeping small interface text readable
Resolution and encoding quality solve different problems. Smaller dimensions remove pixels; stronger compression changes how the remaining picture is encoded. Neither setting promises a particular attachment size.
- Use your original recording and identify the smallest text or control the recipient must read. Start with Original resolution and a moderate compression setting.
- Export one candidate and compare both its size and readability with the source. If it is still too large, choose a smaller width and inspect the same text again.
- Read width options as horizontal dimensions. A tall phone recording does not become a conventional landscape 720p frame merely because a preset label mentions 720p. This control is not a prevent-enlargement switch; a requested width can enlarge a smaller source.
- Keep audio when speech explains the action. Removing it is suitable only when the visual content is sufficient. Check the downloaded file's sound and detail before sharing.
For an authored submission scenario, first remove an irrelevant introduction with Trim Video, then compress the retained content. Duration reduction can help without making the remaining interface smaller. No sample file or percentage saving is claimed.
If a hard upload limit still cannot be met at acceptable quality, shorten or divide the content. Convert Video is a separate format workflow, not a guarantee of further compression.
Limits and quality
The input staging limit is 450 MiB, while practical capacity depends on device memory and media complexity. Re-encoding is lossy. File-size reduction and encoding speed are not guaranteed, and a smaller resolution cannot recover detail missing from the source.
Local processing and engine downloads
The application processes selected media in this browser. The FFmpeg engine and workers load from a third-party CDN when first needed; those requests disclose ordinary connection information. Keep the original files and check your downloaded result. Export needs JavaScript, WebAssembly and worker support.
Frequently asked questions
Why is the compressed video larger?
The source may already use a more efficient codec or lower bitrate. Try a smaller width or a stronger compression setting and compare quality.
Can I batch-compress several videos?
This tool processes one selected video at a time. Merge Videos is a separate workflow for joining clips.
Related workflows
Prepare a shorter recording for sharing
Trim unnecessary material first, then choose a width and quality appropriate to the destination. Inspect the output and compare its actual size with the source.
Before choosing the output
Re-encoding is lossy and can increase size when the source is already efficiently encoded. A compression setting does not promise a fixed saving.
Read the format and processing details above. Keep the original and inspect the downloaded result.