Video Compressor for MP4, WebM, Uploads, Email, and Social Sharing
Compress MP4 or WebM video with quick presets, browser-side quality, resolution, format, and audio controls. FFmpeg is hosted with the site, loads only after you start processing, and this browser-side version is best for short clips under 200MB.
Ready to use
Browser-side · no account · results stay on this page
Drop video here or click to upload
MP4 and WEBM are the safest first-version inputs.
Max file size: 200MB
No video uploaded
Mobile processing guidance
On mobile, start with a short MP4/WebM under 50MB before trying larger clips.
Max 200MB in this browser version.
FFmpeg uses this tab's CPU and memory after you start processing.
If processing stalls, stop and retry with a shorter clip, lower resolution, or higher CRF.
File limit
Use files under 200MB. Smaller clips are more reliable on mobile.
Processing time
FFmpeg loads after you click the action button, then uses local CPU and memory.
Common failures
Unsupported codecs, low memory, very large files, or long clips can fail.
Quick compression presets
Start from a practical target, then adjust CRF, resolution, or audio before processing.
Current CRF 32
H.264 video with AAC audio for broad compatibility.
Output size: No resize needed
Good for social, product demos, and most uploads.
Disable for a smaller silent video.
Engine
ffmpeg.wasm
Output
MP4
Audio
96 kbps
Estimate
Upload first
Next step
Choose a short MP4 or WebM first. On mobile, start under 50MB before trying larger clips.
Output size
No compressed video yet
Format
MP4
Size change
Not ready
FFmpeg is designed to run in the browser only after you start processing, and the large WebAssembly engine is served from this site.
A video compressor reduces file size by re-encoding the video with a quality, resolution, format, and audio target.
Use the quick presets to make a video smaller for Discord, email, web upload, social preview, readable UI demos, or a silent preview, then review the output before downloading.
The settings panel shows a rough output range before processing so you can decide whether to lower resolution, frame rate, CRF, or audio first.
This first browser-side version is best for short MP4 or WEBM clips under 200MB.
Large files and mobile browsers can run into memory limits even before compression finishes, so trim long clips first when possible.
Short local clips under 200MB
Browser-side FFmpeg uses local memory and CPU, so short clips finish faster and are more reliable on mobile.
Clear output goal
Choose whether you want a Discord share, email attachment, web upload, social preview, readable UI text, silent preview, or compatible MP4.
Known target size
Use the rough estimate as a planning signal, then verify the downloaded file because exact size depends on source complexity.
Discord share
Reduce a short MP4 before sending it through chat.
Input
A 90MB, 1080p, 20 second MP4 clip.
Settings
- Preset: Discord share
- Max resolution: 720p
- CRF: 32
Expected output
A smaller MP4 preview that is easier to upload to chat.
Email attachment
Make a quick support clip small enough for an attachment.
Input
A 55MB screen recording with narration.
Settings
- Preset: Email attachment
- Audio bitrate: 64 kbps
- Keep MP4 output
Expected output
A compact support video with audio kept for context.
Silent UI demo
Remove audio and reduce size for a visual-only product demo.
Input
A 30 second product walkthrough where audio is not needed.
Settings
- Preset: Silent preview
- Max resolution: 720p
- Remove audio
Expected output
A silent video preview with lower file weight.
Check the upload limit
Know whether the destination needs a smaller file, a lower resolution, MP4 compatibility, or a silent preview.
Trim long clips first
Shorter source clips compress faster and are less likely to exhaust browser memory.
Pick a target preset
Start with Discord share, Email attachment, Web upload, or Social preview before changing manual settings.
Expect quality tradeoffs
Higher compression can soften UI text, faces, gradients, and fast motion. Preview the output before sharing.
Starting without a target
Pick Discord, email, web upload, social preview, readable UI, or silent preview first. A smaller number alone does not prove the clip is useful.
Using max quality for compression
Very low CRF values can preserve quality but may not reduce size. Start around CRF 28-34 when smaller files matter.
Keeping full resolution unnecessarily
A 4K source often needs a 1080p or 720p limit for meaningful size reduction in browser workflows.
Expecting the estimate to be exact
The estimate is a planning range, not a guarantee. Motion, noise, source codec, and scene changes can move the final size.
Processing huge files on mobile
Large files can exhaust memory or take a long time. Trim or use a desktop browser for heavier work.
Upload limits
Reduce a clip before sending it through a form, chat, or content management system.
Email attachments
Try a lower-resolution MP4 preset when a clip is too large for email or support tickets.
Discord sharing
Use a compact MP4 preset when a short clip needs to travel through a chat workflow.
Social previews
Use a 720p MP4 preset when preparing a short draft for social platforms or mobile review.
Mobile sharing
Lower resolution and audio bitrate when a smaller file matters more than full quality.
Silent previews
Remove audio from short previews when the destination does not need sound.
Web publishing
Prepare a smaller MP4 or WebM for pages, docs, and product updates.
reduce MP4 file size
Use a higher CRF value, lower resolution, or lower audio bitrate when an MP4 is too large for upload.
compress video for Discord
Use a compact MP4 preset with lower resolution, lower audio bitrate, and frame-rate limits for chat sharing.
compress video for email
Use a smaller MP4 preset when the goal is an attachment or support-ticket upload.
compress video target size
Use the rough estimate to decide whether to lower resolution, frame rate, CRF, or audio before processing.
compress video for social media
Use upload-friendly MP4 settings when a platform rejects the original file or takes too long to process it.
CRF controls quality
Higher CRF values usually reduce size more, but the image becomes softer and artifacts become more visible.
Resolution changes matter
Dropping 4K to 1080p or 720p can reduce size more predictably than tiny quality changes.
FPS is a size lever
Lowering to 24 fps or 15 fps can help for short previews, demos, and attachments where motion smoothness is secondary.
Estimate is a range
Use the pre-processing range for planning, then trust the actual downloaded size for final delivery.
Failure fallback
If compression fails, trim the clip, lower resolution, keep source FPS, try MP4 input, or move to desktop tooling.
Audio can be simplified
Lower audio bitrate or silent output helps when the clip is a preview, UI demo, or visual-only attachment.
How is the video processed?
The selected video is designed to be processed in your browser with ffmpeg.wasm based on the current public implementation. Avoid sensitive files unless you have reviewed the implementation.
What file size should I use?
The first browser-side version accepts videos up to 200MB. Smaller files are recommended on mobile devices because compression uses local CPU and memory.
How do I make the video smaller?
Use a higher CRF value, lower the resolution, lower the audio bitrate, or remove audio when a silent result is acceptable.
What settings should I start with?
Use Web upload for balanced browser publishing, Email attachment for smaller files, Discord share for chat delivery, Social preview for platform drafts, Readable UI demo when screen text must stay clear, or Silent preview when sound is unnecessary.
Can I set an exact target size?
This version gives presets and a rough estimated output range before processing. Exact target-size encoding depends on source complexity, motion, codecs, and duration, so always compare the final output size before sharing.
Why can the output sometimes be larger?
Re-encoding can increase size when the source was already heavily compressed, the selected quality is high, or the new codec is less efficient for that clip.
How is the video processed?
The selected video is designed to be processed in your browser with ffmpeg.wasm based on the current public implementation. Avoid sensitive files unless you have reviewed the implementation.
What file size should I use?
The first browser-side version accepts videos up to 200MB. Smaller files are recommended on mobile devices because compression uses local CPU and memory.
How do I make the video smaller?
Use a higher CRF value, lower the resolution, lower the audio bitrate, or remove audio when a silent result is acceptable.
What settings should I start with?
Use Web upload for balanced browser publishing, Email attachment for smaller files, Discord share for chat delivery, Social preview for platform drafts, Readable UI demo when screen text must stay clear, or Silent preview when sound is unnecessary.
Can I set an exact target size?
This version gives presets and a rough estimated output range before processing. Exact target-size encoding depends on source complexity, motion, codecs, and duration, so always compare the final output size before sharing.
Why can the output sometimes be larger?
Re-encoding can increase size when the source was already heavily compressed, the selected quality is high, or the new codec is less efficient for that clip.
Suggested workflow
Build a browser-side video optimization workflow
Compress the clip, convert format when needed, then extract the cover image for publishing.
Guides and examples