Why Datamosh Effect Works Here
Real motion vectors, not a blur
Each frame is split into blocks (8, 16 or 32px) and every block gets its own motion vector, found by matching it against the previous frame. Those vectors then move blocks of the previous output — the same thing a video decoder does when its keyframes go missing.
Its own mode, or a filter
Datamosh is a mode of its own (press 0), with its settings right in the Tracking tab. It’s also in the Post FX list, so you can mosh over a tracking mode, or stack another Post FX such as VHS on top of the mosh.
Bloom and Motion Boost
Bloom keeps re-applying each block’s last motion, so a region keeps swelling and sliding after the movement stops — the duplicated-P-frame bloom. Motion Boost multiplies every vector so smears travel further than the thing that moved.
Recovers like a real codec
The picture comes back in square blocks of clean image popping into the smear, the way an encoder’s intra-refresh does, not as a soft cross-fade. Mosh Strength sets how rarely that happens; at 100% nothing recovers until a keyframe.
No Avidemux or ffmpeg
Traditional datamoshing means deleting I-frames from a file and hoping the player survives it. Here the effect is rendered frame by frame, so what you export is an ordinary MP4 that plays everywhere.
Keyframes on your timing
Keyframe Every snaps the picture back every few seconds for the mosh-and-reset rhythm, Mosh Now starts a fresh smear on the exact frame you press it, and every mosh setting can be animated with keyframes to melt right on the drop.
How to datamosh a video online
- Open Datamosh mode Click Launch the Datamosh Effect, or press 0 in the app to switch to Datamosh mode.
- Load a clip with movement Motion is what drives a datamosh: a dancer, a camera move or a cut all smear well. A static shot barely moshes.
- Shape the melt Raise Mosh Strength and Bloom for a longer, swelling smear, Motion Boost to drag it further, and pick a Block Size. Keyframe Every sets how often it snaps back; Mosh Now starts a fresh smear on the frame you choose.
- Record it Press Record to export the datamoshed video as MP4 or WebM — an ordinary file that plays everywhere.
Datamosh without Avidemux
The classic way to datamosh is to convert a clip to an old codec, delete its I-frames in Avidemux, duplicate P-frames to make it bloom, and hope the file still plays. Vis Exo does the same thing a broken decoder does — it measures each block's motion and applies it to the previous picture instead of the new one — but live, on any video or webcam, with the result exported as a normal file.
Frequently Asked Questions
What is datamoshing?
Datamoshing is a glitch technique built on how compressed video works. Most frames only store motion (“this block moved over there”), and keyframes store the actual picture. Take the keyframes away and the motion keeps being applied to an old picture, so it smears and melts.
Is this real datamoshing or a filter that imitates it?
It uses the same mechanism: motion is measured block by block and applied to the previous output frame instead of the new one. The difference is that it happens live while you watch, instead of by corrupting a video file.
How do I make the smear last longer?
Raise Mosh Strength toward 100%, turn Bloom up, and set Keyframe Every to Never. In Datamosh mode the controls are in the Tracking tab; if you use Datamosh as a Post FX instead, they appear under Post-Processing FX in the Style tab.
Can I datamosh only part of a video?
Yes. Load a video, open Keyframes in the Clip Editor, and set Post-Processing FX to Datamosh for just the time range you want. Mosh Strength can be keyframed too, so the melt can build and release.
Does it work on a live webcam?
Yes. Choose Camera as the source and move around; anything that moves drags the picture with it. The motion search runs every frame, so lower the Resolution setting if a slower device drops frames.
Can I combine datamosh with a VHS look?
Yes. In Datamosh mode, set Post-Processing FX to VHS and the tape look is applied on top of the mosh. That combination is hard to get with traditional datamoshing, where the file itself has to be corrupted.
Is it free?
Yes: free, no watermark and no signup, and your video never leaves your browser.
How do I datamosh a video online for free?
Open the Datamosh effect, load your clip, and press Record. It runs in your browser with no upload, no watermark and no Avidemux or ffmpeg.
What is a datamosh bloom?
A bloom is when the same motion keeps being applied after the movement has stopped, so a region keeps swelling or sliding. The Bloom slider controls how much of each block's last motion carries into the next frame.
Why does my datamosh turn into mush?
Every moving block keeps dragging the old picture, so after a few seconds there's nothing recognisable left. Set Keyframe Every to a few seconds, lower Motion Boost, or use a steadier clip — camera shake moves every block at once.
Can I datamosh on my phone?
Yes. Datamosh runs in your phone's browser on a video from your camera roll or the live camera. If it drops frames, lower the Resolution setting in the Source tab.
