Bitrate
Fewer bits where nothing moves
Cameras record at a high bitrate so nothing is lost while filming. Re-encoding with H.264 at a constant quality spends bits on motion and detail, not on a still background.
MP4 Compressor
Make MP4 videos smaller online, free. Choose how small, keep the MP4 format, no watermark.
- Free to use
- No file stored beyond 1 hour
- Encrypted over TLS 1.2/1.3
- No watermarks
Drag and drop your files here or click to upload.
Maximum file size is 1GB
Like RunConvert? Set us as a preferred source on Google.
Add to Preferred SourcesHow to compress an MP4 video
Three steps, in your browser. Nothing to install.
- 01
Add your MP4 files
Drop up to 20 MP4 or M4V files, or paste a link.
- 02
Pick how small
Every video starts on Balanced. Open a video's settings to make it smaller, lower its resolution or keep more quality, for one video or all of them.
- 03
Compress and download
Each video stays MP4. Download them one by one or all at once.
Which setting should I pick?
Start with Balanced. If the file is still too big for an email or a form, open the settings on its row and pick Smallest file and 720p.
- Smallest fileBiggest size cut. Good for email, WhatsApp and upload limits.Chat · email
- BalancedDefaultMuch smaller, and still looks sharp. Right for most videos.Most videos
- Best qualityA lighter cut with no visible loss. For videos you'll edit or keep.Editing · archive
How the video gets smaller
Three things decide a video's size. The compressor turns each of them down and keeps what you can actually see and hear.
Resolution
Fewer pixels, the biggest cut
1080p has a quarter of 4K's pixels and looks the same on a phone or in a chat app. Only sizes below your video's own are offered, so nothing is scaled up.
Audio
Sound at a sensible bitrate
The soundtrack is re-encoded at 96 to 160 kbps depending on the setting: clear for speech and music, a fraction of the original.
- Formats
- MP4, M4V
- Video codec
- H.264
- Files
- Up to 20 videos, 1 GB each
- Output
- Same format as the input
25 MB
Fit email and upload limits
Gmail attachments stop at 25 MB, and many school portals and chat apps reject large videos. Start with Balanced; if it's still too big, open the settings and pick Smallest file and 720p.
More free video tools
Frequently asked questions
Common questions about compressing MP4 videos with RunConvert.
Yes. Compress MP4 videos for free, without a watermark and without signing up.
Best quality and Balanced keep the picture sharp for phones, laptops and TVs. Smallest file trades some detail for size. Your original is never changed.
A video that was already compressed, like one saved from social media, has little left to remove. Try Smallest file with 720p. The download page shows the change for each file.
Up to 20 videos at a time, up to 1 GB each.
They are encrypted in transit, used only for your compression, and deleted automatically after a few hours.
Ready to compress your video?
Free, no sign-up, no watermark.