MJPEG to WebP Converter

MJPEG to WebP — Still Image or Animation?

This is the question almost everyone arriving here is really asking, and the answer is definite: converting MJPEG to WebP on this page produces a still image, not an animated one. WebP as a format supports animation, but this conversion decodes the frame you select and saves it as a single static picture; ask for several frames and you get several separate .webp files, not one animated file. If you want the motion preserved, Motion JPEG has two animated targets on this site and they are one click away. The comparison below shows exactly what each route gives you so you can pick once and be right.

Side-by-side: What Each Motion JPEG Target Produces

When to Pick WebP

• You need one representative frame — a thumbnail, a poster image, a preview tile — and you want it small.
• The destination is a web page. Per caniuse, WebP is supported by Chrome 32+, Firefox 65+, Edge 18+, Safari on iOS 14+ and desktop Safari 16+, so a still WebP is safe for general web delivery today.
• You are batching frames for a contact sheet or a review gallery and the total byte count matters more than per-frame fidelity.
• You want lossless without PNG's size penalty: Google measures WebP lossless images as around 26% smaller than equivalent PNGs.

When to Pick Something Else

• You want the clip to move. Use MJPEG to GIF or MJPEG to APNG for a short loop, or MJPEG to MP4 for anything more than a couple of seconds.
• The frame is evidence or a master. A lossless PNG or an LZW TIFF is easier to defend than "WebP with lossless switched on", and TIFF is what archives ask for.
• The recipient runs old software. A 2013 print workflow or a legacy case-management system may simply not open WebP; JPG always opens.
• The frame is larger than 16383 pixels on a side. That is WebP's hard dimensional ceiling. Video frames never approach it, but stitched or upscaled images can.

How to Convert MJPEG to WebP

1. Upload Your MJPEG File: Drop it on the upload box or click "Add Files". This page takes the .mjpeg extension, so rename a .mjpg first; the actual container is then identified from the file's bytes, so an AVI or QuickTime file carrying Motion JPEG that has been renamed is handled correctly too.
2. Pick Your Frame Under Frame Selection: Specific Frame with Time (seconds) at 0 returns the first frame. For any later frame in a raw stream, switch to Multiple Screenshots and set a Capture Rate — a raw Motion JPEG stream has no timestamps for a specific time to seek against.
3. Set Quality Preset and the Lossless Switch: Quality Preset defaults to Very High (Recommended); step it down to shrink the file. The separate Lossless? control defaults to No (Recommended) — set it to Yes when the frame must survive intact.
4. Scale if Needed, Then Convert: Image resolution defaults to Keep original; use Preset Resolutions, a percentage or explicit Width x Height for a thumbnail. Convert and download — no sign-up, no watermark.

Lossy vs Lossless WebP for a Video Frame

Frequently Asked Questions

Can I get an animated WebP from my Motion JPEG file?

Not from this conversion. Each selected frame is decoded and written as its own still .webp; choosing Multiple Screenshots produces a numbered set of separate files rather than one animated file. WebP itself supports animation, so this is a property of how this conversion is built, not a limitation of the format. For a moving result use MJPEG to GIF or MJPEG to APNG, both of which genuinely animate, or MJPEG to MP4 for anything beyond a few seconds.

Does the Lossless switch really produce an identical frame?

Yes, and we checked rather than assumed. We extracted a frame from a raw Motion JPEG stream and ran it through the WebP encoder both ways: with Lossless? set to Yes the output matched the extracted frame with zero differing pixels, and it was still smaller than a PNG of the same frame. With the default No, every quality preset we tried altered some pixels. One caveat worth being clear about — "lossless" here means lossless relative to the frame as decoded, which the camera had already compressed as a JPEG.

Why is Lossless marked "No (Recommended)"?

Because for the overwhelming majority of WebP conversions the point is a small file, and lossy WebP is dramatically smaller. Google's own figures put lossy WebP around 30% smaller than comparable JPEG. On a frame that came out of a camera as a JPEG in the first place, that extra generation of loss is usually invisible at normal viewing sizes. Switch it to Yes when the frame is going to be examined closely, enhanced, or presented as a record.

Is a WebP of the frame smaller than just exporting a JPG?

Usually, yes — that is the format's entire reason for existing, and Google measures roughly 30% better compression than JPEG at comparable quality. Whether it is worth it depends on the destination. For a web page, WebP is the better choice on every current browser. For an email attachment, a case file, or a hand-off to someone whose software you do not control, the size saving rarely justifies the compatibility risk and MJPEG to JPG is the safer answer.

Why does entering a time in Frame Selection give me nothing?

Because a raw .mjpeg file is just concatenated JPEG images with no timestamps, no duration and no declared frame rate — there is nothing for a timestamp to point at. Seeking to a non-zero time on such a stream returns no frames, so no file is written. Leave Time at 0 for the first frame, or use Multiple Screenshots, which walks the decoded stream in order rather than seeking, and works reliably. If your file is really a renamed AVI or MOV, convert it from that container and Time will work normally.

How many frames can I pull in one go?

As many as the Capture Rate produces across the clip. Rates run from one frame every 0.1 seconds up to one every 10 seconds, and every interval yields a separate .webp. Since a raw Motion JPEG stream carries no rate of its own, decoders assume a nominal frame rate, so the number of files you get reflects that assumption rather than the camera's real capture speed — a stream of 100 frames yields four files at "1 second per frame".

Does WebP keep transparency from the source?

WebP supports a full 8-bit alpha channel, so transparency is preserved when a source has it. Motion JPEG sources do not: JPEG has no alpha channel at all, so every frame is fully opaque before it reaches the encoder. If you need a transparent background you will have to cut it yourself in an image editor after conversion — no converter can invent alpha that was never recorded.

What happens to my file after I convert it?

It is uploaded over an encrypted connection, converted on our servers, and deleted automatically after a few hours. Nothing is shared, published or reused. There is no account requirement, no watermark on the output, and no cap on how many frames you extract from a clip.