Online MP4 Editor
Cut, Crop, and Edit MP4s
MP4 is the universal language of video. It works on iPhone, Android, Windows, and Mac. But editing one shouldn't require installing a 5GB program. FlowVideo AI's Online MP4 Editor runs in your browser.
Trusted by creative teams at
MP4 Editor
Cut, crop, and edit instantly
Trim Range
Edit Preview
Your edited MP4 will appear here. Upload a video and select your editing tools.
The Precision Scalpel
You recorded a Zoom call. Ideally, you just want to trim the first 5 minutes of small talk. You have a Twitch clip. Ideally, you want to crop it to vertical for TikTok. For these simple tasks, professional software is overkill. It's like using a chainsaw to cut butter. You need a scalpel.
FlowVideo AI's MP4 Editor is that scalpel. It loads instantly. It runs in Chrome/Safari. It allows you to perform 'Lossless Trimming' (cutting without re-encoding quality loss), merge multiple files, add subtitles, and export in seconds.
It is the utility knife for the modern creator.
Zero Install
Edit in your browser
Why Use an Online MP4 Editor?
The format that runs the world.
Universal Compatibility
No more 'File not supported.' Our editor has a built-in transcoding engine. Upload MOV, MKV, or AVI—we convert to standard MP4 H.264 automatically. You don't need to know what a 'Container' is.
Lossless Operations
Most editors re-encode the whole video, degrading pixels (Generation Loss). For simple cuts, we perform 'Stream Copying'—snipping at the I-frame. Export is instant, quality is mathematically identical to source.
Collaborative Speed
A file on your hard drive is stuck there. An MP4 in our cloud editor has a URL. Email it to a colleague. They open the same project, make a tweak, re-export. No file transfer required.
Security (Local Mode)
For sensitive MP4s (e.g., internal legal Zoom calls), we offer 'Local Edit' mode. The file is processed purely in your browser's memory (WASM). Never uploaded to servers. As secure as editing offline.
The Technology: Browser-Native Editing
Cutting without the cloud bill.
Client-Side FFmpeg
We ported the legendary FFmpeg library to WebAssembly. Your browser can read frame metadata, extract audio waveforms, and perform complex muxing—without sending data to a backend server.
Smart Rendering
Drop a 30fps clip and a 60fps clip on the same timeline—we automatically 'Conform' them to a single frame rate to prevent playback jitter. Audio too quiet? We apply a +6dB gain automatically.
Zero Upload Latency
Drag a 1GB file in, and you can scrub the timeline immediately because the data never leaves your machine. No waiting for uploads. Start editing instantly.
Quick Edits Guide
From Clip to Share.
Upload
Drag & Drop your MP4 from desktop or phone camera roll. The editor verifies file integrity (MP4 headers can get corrupted).
Trim & Cut
Drag the yellow handles at start/end to trim. Move playhead to middle, press 'Split.' Delete sections. Drop a second MP4 to merge—they snap together.
Enhance
Click 'Crop' and select '9:16' to isolate the speaker for mobile. Add text headers. Right-click → Speed → 2x to speed up tutorials.
Export
Format: MP4. Choose 'Source Quality' (same bitrate) or 'Compressed' (smaller file for email). Download to device.
Troubleshooting MP4 Issues
⚠️ No Audio
Codec issue (AC3/DTS).
✓ Our editor auto-converts unsupported audio to AAC (Universal).
⚠️ Green Screen
Corrupt GPU driver.
✓ Toggle 'Hardware Acceleration' off in Chrome settings or use our cloud render.
⚠️ Sync Drift
Variable Frame Rate.
✓ We apply 'Force CFR' to lock audio to video frames.
⚠️ Upload Slow
Large file.
✓ Use 'Local Mode' to edit without uploading.
Tools Compared
| Feature | QuickTime Player | FlowVideo Online | Adobe Premiere |
|---|---|---|---|
| Trim | Yes | Yes | Yes |
| Merge | Yes (Clunky) | Yes (Timeline) | Yes |
| Text/Overlays | No | Yes | Yes |
| Crop/Resize | No | Yes | Yes |
| Install | Pre-installed | None (Web) | Heavy |
| OS | Mac Only | Any | Mac/PC |
Industry Use Cases
Sales Teams
Take a 30-minute Loom recording. Cut it down to a 2-minute feature highlight. Send to prospect. Close the deal.
Teachers
Take three 10-minute Zoom recordings (Part 1, 2, 3). Merge them into one 'Master Class' MP4 file for students.
Gamers
Take a 4-hour stream VOD. Extract the 30-second 'Penta-Kill.' Add text 'Let's Go!' Export for Twitter.
HR
Open screen recording. Add a 'Blur' overlay on top of the employee ID column. Export a safe version for training.
What Users Are Saying
It just works.
“I need to cut demo recordings constantly. This is the fastest tool I've found. Drag, trim, export. No account required for basic edits. Game changer.”
Rachel M.
Sales Manager
“I merge my lecture recordings weekly. The timeline interface is intuitive and the lossless export means my students get the best quality. Highly recommended.”
Professor Alan T.
University Instructor
“I clip my best moments directly from the VOD. The speed adjustment feature is clutch for dramatic slow-mo replays. Export to Twitter in seconds.”
GamerzHD
Twitch Streamer, 50K Followers
Frequently Asked Questions about MP4 Editing
Sometimes you don't need a movie studio; you just need to cut a file. FlowVideo AI's Online MP4 Editor respects your time. It is the fastest path from 'Raw File' to 'Done.'