Do not re-encode a compatible MOV by default
A MOV with compatible H.264 video and AAC audio can often move to an MP4 container while retaining its media packets. That preserves quality and is much faster than decoding the whole clip.
Local MP4 converter
Make an MP4 when the tracks can stay compatible.
Inspect the selected video first. Compatible H.264 video and AAC audio can be remuxed into MP4 without re-encoding; other tracks may need a browser-supported local conversion.
Your video stays on this device. No upload, account, or server-side processing job.
Browser-local workspace
Open the private video workspace when you are ready.
Choose one local MP4, M4V, MOV, or WebM file. JavaScript activates a browser-native preview and capability check; available conversions depend on the codecs supported by this device.
No upload, account, or server-side media job.
Open private workspace Loads only after you choose to open it.
Keep advanced choices out of the way
The basic choice is an MP4 output with maximum compatibility or a smaller-file preference. A remove-audio option belongs in this same converter because it can be a packet-copy operation when the output container remains compatible.
Private browser processing
Your video remains in your hands.
Aftermath reads selected video bytes only in the current browser. Unsupported codecs are reported clearly rather than sent to another service. High-resolution conversion can use substantial device battery and processing.
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