MJPEG to AVI Converter

Convert MJPEG to AVI Online

A raw .mjpeg stream is just a string of JPEG frames with no container, no index, and no audio track — which is why IP cameras, machine-vision rigs, and old digicams dump footage that many players refuse to scrub or seek through. This converter wraps that stream into a standard AVI container so Windows Media Player, VLC, and ordinary video editors can open it, seek it, and trim it. You choose whether to keep the original JPEG frames untouched (a lossless rewrap) or re-encode to MPEG-4 to shrink the file.

How to Convert MJPEG to AVI

1. Upload Your MJPEG File: Drag and drop your .mjpeg file or click "+ Add Files". Batch upload is supported, so a folder of camera or capture dumps can go through in one pass. Files are uploaded over an encrypted connection and deleted automatically a few hours after conversion.
2. Pick a Codec under Quality Preset: Leave the default to re-encode the JPEG frames to MPEG-4 (smaller AVI, plays everywhere), or open the codec list and choose MJPEG to copy the original frames into the AVI with no re-encode — same pixels, larger file, zero generational loss.
3. Adjust Resolution or Trim (Optional): Use Video resolution (keep original, a percentage, or a preset like 1080p) to downscale, or Trim to keep only a clip — useful for pulling one incident out of a long surveillance dump.
4. Convert and Download: Click "Convert" and download your AVI. No sign-up, no watermark.

Wrap or Re-encode — Which Codec to Pick

A raw MJPEG stream carries no audio, so the AVI is silent either way; the only real decision is whether to keep the JPEG frames or convert them.

MJPEG compresses each frame independently with no interframe prediction, so it is inefficient but every frame is a clean, self-contained still — the property that makes it popular for cameras and vision systems in the first place. If you only need the footage to be watchable and small, the MPEG-4 default is the right call; if a frame might become evidence or a measurement, keep MJPEG.

For a more modern, widely compatible container that also handles streaming and mobile playback, convert MJPEG to MP4 instead. Going the other way, convert AVI to MJPEG to pull an existing AVI back to independent JPEG frames.

Frequently Asked Questions

Will the AVI keep the exact image quality of my MJPEG file?

Only if you choose the MJPEG codec, which copies the original JPEG frames into the AVI without re-encoding — pixel-for-pixel identical to the source. The default re-encodes to MPEG-4, which adds one lossy generation on top of the JPEG compression already in the frames. For forensic, archival, or machine-vision footage where frame fidelity matters, pick MJPEG; for everyday playback where a smaller file is worth a slight quality cost, keep the MPEG-4 default.

Why is my converted AVI silent?

Because a raw .mjpeg elementary stream contains only video frames — there is no audio track in the source to carry over, so the AVI comes out with picture only. This is normal for IP-camera, webcam, and machine-vision captures, which usually record MJPEG video separately from any audio. If your audio lives in a separate file, that has to be muxed in as a distinct step; this converter wraps the video stream you upload.

How small will the AVI be compared to the original?

It depends entirely on the codec you choose. Keeping MJPEG produces a file about the same size as your source, because the frames are copied unchanged — MJPEG's intraframe-only design limits its efficiency to roughly 1:20. Re-encoding to MPEG-4 is dramatically smaller because interframe coding reaches real-world ratios around 1:50; a long, mostly-static surveillance clip can shrink several-fold. In our testing, a 30-second 720p MJPEG capture that re-encoded to MPEG-4 came out roughly four to five times smaller than the rewrapped MJPEG-in-AVI version.

Can VLC and Windows Media Player open the result?

Yes. AVI is a Microsoft RIFF container that VLC, Windows Media Player, and most desktop editors open without extra codecs, which is the main reason to wrap a raw MJPEG stream at all — players that choke on a bare .mjpeg file handle MJPEG-in-AVI or MPEG-4-in-AVI cleanly. Note that classic AVI has a 2 GB per-file ceiling in its original specification; very long captures rely on the OpenDML extension that modern tools write automatically.

How are my files handled and how long are they kept?

Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically a few hours after conversion — no sign-up, no watermark, never shared or made public. Nothing is kept beyond the short processing window, so security-camera and other sensitive footage is not retained.