If you have spent any time optimizing images for the web, you have run into WebP. It promises smaller files than JPEG and PNG while keeping quality high, and major browsers now support it almost universally. But what exactly is WebP, how does it pull off those savings, and when should you actually use it instead of the formats you already know? This guide answers all three questions in plain language.
What Is WebP?
WebP is an image format developed by Google and first released in 2010. Its goal was simple: deliver the same visual quality as existing formats in a smaller file, so web pages would load faster. WebP is unusual because it supports several things at once. It can do lossy compression like JPEG, lossless compression like PNG, and transparency through an alpha channel, also like PNG. It even supports animation, making it a potential replacement for GIF as well.
In other words, WebP is a single format that tries to cover the jobs of three older ones, and it usually does so with smaller files.
How WebP Achieves Smaller Files
WebP borrows advanced techniques from video compression. Its lossy mode uses prediction, where the encoder guesses the contents of a block from neighboring blocks and only stores the difference. This is more sophisticated than the block-based approach JPEG uses, so WebP can represent the same image with less data. Its lossless mode uses smarter entropy coding and palette handling than PNG. The practical result is that WebP commonly produces files 25 to 35 percent smaller than a comparable JPEG, and often much smaller than an equivalent PNG.
Lossy, Lossless, and Transparency in One
What makes WebP unusual is that a single format can switch modes depending on the content. For a photograph you use lossy WebP, which behaves like a smarter JPEG. For a logo or diagram you use lossless WebP, which behaves like a smaller PNG. And in either mode you can include transparency. This flexibility is why some sites standardize on WebP for nearly all their imagery, since one format covers cases that previously needed two or three.
WebP vs JPEG vs PNG
The clearest way to understand WebP is to compare it directly with the formats it aims to replace.
- WebP vs JPEG: WebP usually wins on size at the same visual quality and adds transparency support, which JPEG lacks. JPEG still has the edge in universal compatibility with old software.
- WebP vs PNG: For graphics with transparency, WebP is typically far smaller while keeping crisp edges. PNG remains the safest choice for maximum compatibility.
- WebP vs GIF: Animated WebP is smaller and supports more colors, though GIF is still more widely embeddable.
For a deeper look at the photographic side, see our guide on JPEG quality versus file size, and for graphics our PNG compression guide.
The Pros and Cons of WebP
WebP is excellent but not perfect. Weigh these before committing.
- Pro: smaller files mean faster pages and lower bandwidth costs.
- Pro: one format handles photos, graphics, transparency, and animation.
- Pro: broad support in every current major browser.
- Con: older software and some email clients may not open WebP.
- Con: editing WebP directly is less convenient than JPEG or PNG in some tools.
When Should You Use WebP?
The decision comes down to where the image will live.
- For modern websites, use WebP for photos and graphics to cut page weight, with a JPEG or PNG fallback for the rare old browser. Our web image guide shows how this fits a full workflow.
- For email attachments, stick with JPEG, since some mail clients still struggle with WebP.
- For sharing with non-technical people, JPEG remains the safest bet for guaranteed compatibility.
- For archiving originals, keep a high-quality master in JPEG or a lossless format and export WebP as needed.
Compressing and Converting WebP
Already have WebP files that are larger than necessary? You can shrink them just like any other image. Use the WebP compressor to reduce them with a live preview. If you need to go the other direction and turn a photo into a small WebP, or compress a JPEG instead for maximum compatibility, the JPEG compressor and PNG compressor cover those formats. A browser tool like compressjpeg.onl handles all of them locally without uploading your files.
WebP and SEO: Does It Matter?
Because WebP files are smaller, pages that use them load faster, and page speed is a genuine ranking factor through Core Web Vitals. Switching photos and graphics to WebP can lower the Largest Contentful Paint, one of the metrics Google measures, especially on image-heavy pages. So WebP indirectly helps SEO by improving performance rather than through any special treatment of the format itself.
That said, the gains come from the smaller bytes, not the file extension. If you resize and compress your JPEGs properly, you capture most of the same benefit. WebP simply lets you go a little further. The practical recommendation for site owners is to serve WebP where the platform supports it, with a JPEG fallback, and to focus first on the fundamentals of resizing and sensible compression covered in our web image guide.
Handling Browser Fallbacks
The cleanest way to use WebP on the web is to let the browser choose. Modern HTML lets you offer a WebP source with a JPEG or PNG fallback, so capable browsers get the smaller file while older ones still see an image. Most content platforms and image CDNs now handle this automatically, which removes the main historical objection to adopting the format.
Worth remembering is that WebP is no longer the newest format on the block. Even more efficient successors are emerging, and the landscape will keep shifting. But WebP occupies a sweet spot today: it is meaningfully smaller than JPEG and PNG, it is supported everywhere that matters, and the tooling around it is mature. That combination makes it the safe, practical choice for most people right now, where newer formats still face the support gaps that WebP itself has already overcome. Adopting WebP gives you most of the available savings without betting on a format the wider web cannot yet reliably display.
In short, WebP is the format to reach for when you want smaller files without sacrificing quality, and JPEG remains the dependable fallback for maximum compatibility. You do not have to choose one forever; serve WebP where it works and JPEG where it must, and you get fast pages today without locking yourself out of any device. Understanding the trade-off, rather than chasing the newest format, is what keeps your images both small and reliable.
For everyday users who simply want smaller photos to share, the practical takeaway is reassuringly simple. You rarely need to think about WebP at all unless you run a website; a well-compressed JPEG handles email, messaging, and social media perfectly. Save WebP for the web, where its smaller files genuinely speed up your pages, and lean on familiar JPEG everywhere compatibility matters most. Knowing when each format earns its keep is more valuable than always reaching for the newest option.
Conclusion
WebP is a genuinely modern format that delivers smaller files than JPEG and PNG while supporting transparency and animation in a single package. For websites it is an easy performance win, while JPEG still rules where universal compatibility matters most. Understand the trade-off and you can pick the right format for every situation. Want to optimize images across formats? Start with the free JPEG compressor and explore the WebP and PNG tools alongside it.