Free online video editor — cut, speed up and slow down video in your browser
Drop in an MP4, MOV, MKV, WebM or AVI file, mark the part you want to remove, accelerate or stretch, and download the result. The video is processed on your own machine — it never leaves the tab.
Drop your video here
or click to browse — MP4, MKV, MOV, WebM, AVI and more
How to cut, speed up or slow down a video online
Three steps, no account, no upload queue. The whole thing happens between your file picker and your downloads folder.
Open your video
Drag a video file onto the drop zone or click to browse. MP4, MKV, MOV, WebM and AVI all work. The file is read straight into the page — there is no upload progress bar because there is no upload.
Mark the section on the timeline
Right-click anywhere on the timeline to drop a Cut, Speed up or Slow down edit at that exact point, or move the playhead and press "+ Add edit". Drag the handles or type start and end times to the second, or use the keyboard shortcuts — I and O set the active range from the playhead, Space plays and pauses.
Apply and download
Every edit you stacked is turned into a single FFmpeg filter graph and run once. When the progress bar finishes you get a normal video file back, watermark-free: preview it inline, then download it under the original file's name.
Three edits you can make to any section
Select a range on the timeline and apply one of three operations to it. Stack as many as you want — they are all applied together in one encode.
Cut a section out
Mark a start and an end time and the segment between them is removed. What comes before and what comes after are re-joined, so the video gets shorter instead of gaining a freeze frame.
For dead air at the front, a fumbled take in the middle, or a doorbell in the background.
Speed up a section
Pick a segment and give it a multiplier — 1.5×, 2×, 4×, 8× or a value you type. Only the selection is sped up; everything around it keeps playing at normal speed.
For compressing a slow build, an install bar, or a long walk between two useful shots.
Slow down a section
The same selection, in the other direction: 0.75×, 0.5×, 0.25× or custom. Audio is stretched to match so it stays in sync with the picture.
For showing a fast movement frame by frame, or holding on a moment for effect.
An online video editor that never uploads your video
Most free online video editors are a web form in front of a rendering farm. You hand over the file, it is copied to storage you do not control, a server re-encodes it, and you download the result — usually with a watermark, a length cap, or a sign-up wall between you and the download button. The upload is the slowest part of the process and the part you can least undo.
This editor inverts that. The video decoder, the filter graph and the encoder are FFmpeg compiled to WebAssembly by the ffmpeg.wasm project, running inside the same browser tab you are reading this in. Your file is read from disk into the page's memory and written back out as a download. There is no server-side copy because there is no server-side step — the full walkthrough of what happens when you press Apply spells out every stage.
The practical consequences: it works on a video you would not be comfortable sending anywhere, it works with no network connection once the page and the engine are cached, and the only ceiling on file size is how much memory your own device can spare. The trade is that the encoding uses your CPU rather than somebody else's, so a long 4K clip takes longer here than it would on a rented server.
None of that is worth much as a claim you have to take on trust, so the no-upload page lists every request this site makes in either direction and shows you how to check it yourself in your browser's own Network tab. It takes about ninety seconds and it works on any tool you are evaluating, not just this one.
No upload, no queue
The file is read locally with the File API. Nothing is transmitted, so there is no upload wait and no copy left behind on someone else's disk.
No account, no watermark
No sign-up, no email, no billing, and nothing is stamped onto the output. The file you download is the file FFmpeg produced.
No hard size limit
There is no server-imposed cap. The real limit is your device's RAM, because the input and the output both live in memory while the edit runs.
Works offline after first load
Once the page and the ~32 MB WebAssembly engine are in your browser cache, the editor keeps working with the network switched off.
Which video formats you can edit and export
On the way in, anything your browser and FFmpeg can both open: MP4 and MOV from phones and cameras, MKV from screen recorders and downloads, WebM from browser capture, and older AVI files. The timeline preview is drawn by the browser's own video element, so a file the browser cannot play back will still be edited correctly — you just will not get a scrubbable preview of it.
On the way out you pick MP4, MKV, MOV or WebM. MP4, MKV and MOV are written with H.264 video and AAC audio, which is the combination that plays everywhere from an iPhone to a smart TV. WebM is written with VP8 video and Opus audio instead, because those are the codecs the WebM container is defined around; VP8 encoding in WebAssembly is noticeably slower than H.264, so pick MP4 unless you specifically need WebM.
There is also a max-resolution control. Leaving it on "Original" keeps the source dimensions; choosing 1080p, 720p or 480p scales the output down, which is the quickest way to make a long clip encode faster and land smaller. It only ever scales down — a 480p source is never blown up.
The formats page goes through each container properly — what codecs it carries, why an MKV or an AVI often will not show a preview even though it edits perfectly well, and which output to pick for what you are doing.
The limits, stated plainly
The engine is a ~32 MB download, once. The first time you apply an edit, the browser fetches the FFmpeg WebAssembly core. On a slow connection that is a real wait before anything starts. It is cached afterwards, so every later edit — and every later visit — begins immediately.
Every edit re-encodes. Cutting, speeding
up and slowing down all run through FFmpeg's filter_complex
pipeline, and you cannot stream-copy a stream you are filtering. The output is
encoded with libx264 at the ultrafast preset
and CRF 28 — chosen because a browser tab is a slow place to run an encoder.
On typical footage the difference is hard to see; on a very clean, very detailed
source you may notice it.
Everything lives in RAM. The input file, FFmpeg's virtual filesystem and the finished output all sit in memory at the same time. A few hundred megabytes is comfortable on most machines; multi-gigabyte 4K footage on a phone is where tabs start to die. If you are on mobile, expect it to work and expect it to be slow — desktop is the better place for anything long.
It is a trimmer, not a suite. There is no multi-track compositing, no titles, no transitions, no colour grading. Three operations on one timeline, done well, and nothing else.
More detail on all of the above in the questions about editing video in the browser.
More on cutting and retiming video
The editor is three operations on a timeline. Everything that makes those three operations behave the way they do — codecs, keyframes, frame rates and where your file goes — is written up here.
A video editor that never uploads your file
Every request this site makes, in both directions, and a ninety-second method for verifying the claim yourself in DevTools.
Supported video formats
MP4, MOV, MKV, WebM and AVI in, MP4, MOV, MKV or WebM out — which codecs each carries and which export to choose.
Trim a video to a specific length
Hitting a hard duration target for a Reel, a Short or a status post, and what to do when the content will not fit.
How browser video editing works
The WebAssembly engine, the in-memory filesystem, the filter graphs, and why re-encoding is unavoidable.
Trim a video to one section
Mark the part you want to keep, press "Keep only this part", and everything before and after it is cut away in one pass.
Convert MOV, MKV, WebM or AVI to MP4
Load a file, pick a different output format and press Convert video — no edits needed, nothing uploaded, still a full re-encode.
Remove the audio track
Tick mute and the output is written with no audio stream, on its own or alongside cuts and speed changes.
Downscale to 1080p, 720p or 480p
Cap the output resolution to make a long clip encode faster and land smaller; it only ever scales down.
Start with these guides
Four things that explain most of what feels arbitrary about editing video, and one of them is a method for checking any tool's privacy claim rather than believing it.
- How to trim a video without losing qualityTrimming only loses quality if the video gets re-encoded. Here is when that happens, when it does not, and the trade you are making either way.
- How to speed up only part of a videoMost editors apply one speed to the whole clip. What a per-section speed change actually does to frames and audio, and how to do it in a browser or in FFmpeg.
- How to check if an online video editor uploads your fileEvery browser tool claims to be private. You can verify the claim in about ninety seconds with the tools already in your browser. Here is exactly how.
- Trimming large video files online: what the real limit isServer-based tools cap file size because your upload costs them money. A browser tool's ceiling is the WebAssembly heap; here is how to work within it.