About WebP
Google released WebP in 2010, deriving its lossy compression from the VP8 video codec. The pitch was simple: JPEG-quality photos in files typically 25–35% smaller — and it delivered. WebP also has a separate lossless mode that usually beats PNG, and unlike JPEG it supports alpha transparency in both modes. Today every modern browser displays it, and much of the web serves images as WebP by default.
That default is probably why you are here. Saving an image from the web often hands you a .webp file that older editors, photo viewers, and upload forms refuse to open. Convertmaxxing converts WebP to JPG or PNG for compatibility — and in the other direction, turns your JPEGs and PNGs into leaner WebP files for your own site. Everything runs in your browser; nothing is uploaded. Note that animated WebP is not supported here — this tool converts still images only.
Strengths
- Typically 25–35% smaller than JPEG at the same visual quality
- Both lossy and lossless compression in a single format
- Alpha transparency even in lossy mode — something JPEG cannot do
- Displayed natively by every modern browser
Limitations
- Older desktop software and some upload forms still reject it
- Animated WebP is not supported here — conversions are still-image only
- Edged out by AVIF and JPEG XL on pure compression efficiency
Two formats wearing one file extension
WebP is really two different compression schemes that happen to share a container and an extension. Lossy WebP borrows the intra-frame coding from the VP8 video codec: it predicts each block from its already-decoded neighbours and stores only the difference, which is a fundamentally smarter starting point than JPEG’s independent 8×8 blocks. Lossless WebP is an entirely separate design, using colour transforms and a dictionary coder that typically beats PNG by 20–30%.
Because the two modes are so different, generic advice about WebP is often wrong for your specific file. A lossless WebP of a screenshot and a lossy WebP of a photograph share nothing but a header. It also means WebP can do something neither JPEG nor PNG can: lossy compression with a full alpha channel, so a photographic image with a soft transparent edge does not have to be stored losslessly just to keep its transparency.
Why you keep ending up with .webp files you did not ask for
Most large websites now serve WebP automatically. The server checks what your browser advertises support for and sends the smallest format it can — so the JPEG you think you are looking at was delivered as WebP. When you right-click and save, you get the file that was actually sent, not the format you expected, and that is how people accumulate folders of .webp images without ever choosing the format.
The friction shows up later: an older version of Photoshop will not open it, a job application portal rejects the upload, a client asks why they cannot double-click the file. Converting to JPEG or PNG solves it immediately. Worth knowing that converting a lossy WebP to PNG will produce a much larger file without improving quality — if the source was lossy, JPEG is usually the more sensible destination unless you need transparency.
Frequently asked questions
- Why will my WebP file not open in Photoshop or Windows Photo Viewer?
- Browser support for WebP arrived long before desktop application support. Recent versions of Photoshop handle it natively and Windows added support in a system update, but older installations do not, and plenty of specialist tools still refuse it. Converting to JPEG or PNG is the reliable fix when you need to hand the file to software you do not control.
- Is WebP lossy or lossless?
- It can be either — they are two separate compression modes sharing one file extension, and nothing in the filename tells you which one you have. Lossy WebP competes with JPEG; lossless WebP competes with PNG and generally wins by 20–30%. Both modes support transparency, which is one of WebP’s genuine advantages.
- Does converting WebP to PNG restore quality?
- No. If the WebP was lossy, the discarded detail is already gone, and PNG will faithfully preserve the result — artifacts included — in a considerably larger file. Convert to PNG when you need transparency or a lossless working copy for editing, not in the hope of recovering quality.
- Can I convert an animated WebP?
- Not here. Convertmaxxing handles still images only, and rather than silently keeping the first frame and discarding the animation, animated conversion is left out entirely. If your file is an animated WebP, this tool is not the right one for it.