What is WebP?

Right-click 'Save image' on the web and you'll often get a .webp file instead of a .jpg. Here's what that format actually is, and what to do when something refuses to open it.

WebP in one sentence

WebP is a modern image format built for the web. It does the job of JPG, PNG and GIF at once, usually at a smaller file size than any of them, and almost every browser you use today already reads it without you noticing.

Where WebP came from

Google released WebP in 2010. The lossy side of it is not a clean-sheet invention, it reuses the intra-frame compression from VP8, a video codec Google acquired along with a company called On2 Technologies the year before. Compressing a single still frame well is a large part of what a video codec already has to do, so building an image format on top of one was a shortcut that worked.

The goal was explicit from the start: shrink the images that make up most of an average web page's weight, without visitors noticing a drop in quality. Google published its own comparisons at launch claiming meaningful savings over JPG and PNG, and pushed the format through the one channel it fully controlled, Chrome, long before anyone else adopted it.

That is also why WebP took a decade to become the safe default it is now. A format only helps once the software people already have can open it, and for years, most of it couldn't.

How WebP actually works

WebP is really two formats sharing one file extension. Lossy WebP compresses the way a video codec compresses a frame, predicting blocks of pixels from their neighbours and storing the difference, which is where most of the size saving comes from. Lossless WebP throws none of the data away, it re-encodes the exact pixels using a different, dedicated algorithm, and is the mode to reach for when the source is already something like a screenshot or line art rather than a photo.

Both modes support an alpha channel, so a WebP can be fully transparent the way a PNG can, something JPG has never been able to do. WebP can also hold an animation, playing the role GIF used to, with a far larger colour palette and far smaller files for the same motion.

One file extension doing three different jobs depending on how it was encoded is the source of a lot of the confusion around this format. A '.webp' tells you nothing about which mode was used until you open it.

WebP vs JPG

For an ordinary photograph, lossy WebP is the fairer comparison to JPG, since that is the situation both formats are built for. Google's own published testing put lossy WebP at roughly 25 to 34% smaller than a JPG of comparable visual quality, and independent tests since have generally landed in a similar range, though the exact number moves around depending on what is actually in the photo.

A dense, detailed scene, foliage, gravel, fabric texture, tends to compress less impressively than a photo with smooth areas of sky, skin or a plain background, because there is simply less redundancy for either format to exploit. Numbers quoted for 'WebP vs JPG' are always an average across a test set, never a promise for your specific photo.

The one thing JPG will always win on is reach. It has been readable by absolutely everything with a screen since 1992. WebP is readable by nearly everything now too, but 'nearly' is still doing work in that sentence, and it is why the fallback path in this guide exists.

WebP vs PNG

Against PNG the comparison changes shape, because PNG is always lossless and WebP does not have to be. Lossless WebP against lossless PNG is the fair fight, and Google's own figures put lossless WebP at roughly 26% smaller on average, for pixel-identical output.

Where WebP pulls further ahead is when a PNG is being used for a photograph, which happens more often than it should, usually because someone wanted guaranteed transparency and PNG was the format they knew had it. Lossy WebP with alpha gets you that same transparency at a JPG-like file size instead of a PNG-like one, which is a large saving for exactly the kind of image, a product photo on a white background, a graphic with a soft drop shadow, that ends up needing both.

For flat-colour graphics, icons and line art, lossless WebP and PNG tend to land close to each other, and neither has a decisive edge. This is the one matchup where picking WebP is about universal support and one-format-does-both convenience more than a clear size win.

WebP vs GIF

This is the least competitive of the three. GIF is limited to a palette of 256 colours, dates from 1987, and has never supported real alpha transparency, only a single colour designated as fully see-through, on or off, no partial blending at the edges.

Animated WebP supports full 24-bit colour, real alpha transparency with smooth edges, and typically produces a fraction of the file size for the same clip. There is no scenario left where GIF is technically the better format, only ones where GIF is the format a particular platform still insists on.

Some chat apps and older content management systems still expect a .gif specifically for an animation, regardless of what would actually play. That is a platform limitation, not a quality argument, and it is the main reason GIF has not disappeared yet.

Where WebP support stands today

Chrome has supported WebP since it introduced the format. Firefox added support in version 65, released in January 2019. Safari was the holdout, adding it only in Safari 14, alongside macOS Big Sur and iOS 14, both in 2020. Edge inherited support once it rebuilt itself on Chromium in 2020.

In practice that means every browser released in the last several years handles WebP with no plugin and no setting to change. The gap that remains is not really about browsers any more, it is older desktop software: some image editors, some printers' upload portals, some legacy line-of-business systems, and Windows' old built-in Photo Viewer still don't open a WebP file directly.

Windows 10 and 11 can gain WebP thumbnails and Photos app support through the free 'WebP Image Extensions' add-on from the Microsoft Store, the same pattern Windows uses for HEIC. Installing it fixes viewing. It does not give you a way to batch-convert a folder of them, which is usually the actual problem when someone goes looking for a fix.

When you'll actually run into a WebP file

The most common way people end up with one without asking for it: right-clicking an image on a website and choosing 'Save image as'. Modern browsers request whichever format the site is willing to serve, and most sites now serve WebP to a browser that says it can handle one, so the file that lands in your Downloads folder is often WebP even though the page just looked like an ordinary photo.

The second most common way is a screenshot or export from a design tool that defaults to WebP for its smaller size, which is fine until you try to attach it somewhere that only accepts JPG or PNG, an older form, a print submission, certain document templates, and it is quietly rejected.

Neither situation means anything is wrong with the file. It means the tool on the other end has not caught up yet, and converting is the fix.

Converting WebP to JPG or PNG

The reason to convert is almost always compatibility, not quality, WebP itself is fine, the destination just doesn't read it. Drop the file into the WebP converter on this site and pick JPG for photos headed somewhere general-purpose, or PNG if you specifically need transparency preserved or the source was a lossless graphic.

The conversion happens in the browser tab itself, nothing is uploaded to do it. You can confirm that directly: load the page, disconnect from the internet, and convert a file anyway, it still works because everything needed was already downloaded the moment the page opened.

Batch conversion covers up to 200 files at once if you are clearing out a folder of them rather than dealing with one, and the output keeps the original filename with a new extension, so a large batch stays recognisable.

Should you use WebP yourself

If you're publishing to the web, yes. Every current browser reads it, the size saving is real, and most site platforms and content management systems now handle serving it to visitors automatically, sometimes generating it from a JPG or PNG you upload without you doing anything extra.

Keep your original photos in whatever format your camera or phone produced, HEIC, JPG, whatever, and treat WebP as an output format for publishing rather than an archival one. If you ever need to edit the photo again, you want the original, not a lossy copy of a lossy copy.

For anything you're sending directly to another person rather than publishing, a work document, an email attachment, a form upload, JPG or PNG is still the safer default simply because you cannot see what software is waiting on the other end.

Editing and re-saving a WebP file without losing more than you have to

If you open a lossy WebP in an editor, make a change, and save again as WebP, you incur another round of lossy compression stacked on top of the first, the same generational-loss problem that has always applied to JPG. It is worth knowing which mode you are actually dealing with before you resave, because the two modes behave completely differently under repeated editing.

Reopening a lossless WebP and saving it again as lossless loses nothing at all, the same way resaving a PNG doesn't degrade it. Reopening a lossy WebP and saving it again as lossy compounds the loss a second time, exactly the way saving a JPG twice does. If you expect to edit an image more than once, keep working from a lossless master and only export to lossy WebP at the very end.

Software support for editing WebP directly is not the obstacle it used to be. Recent versions of Photoshop, GIMP and Affinity Photo all read and write it without a plugin. Where people still hit a wall it's almost always an old version rather than a fundamental gap, updating the software fixes it faster than converting around it does.

WebP animation, in a bit more detail

An animated WebP is built from a sequence of frames the same way an animated GIF is, but the two formats store that sequence very differently. GIF re-draws restricted regions using a fairly primitive scheme built in the late 1980s. WebP can store only what actually changed between one frame and the next, using the same kind of prediction its still-image compression uses, which is a large part of why the files end up so much smaller for the same clip.

Colour is the other major gap. GIF's 256-colour palette was already a serious limitation for photographic content in 1987, and it hasn't gotten less limiting since. An animated WebP carries full 24-bit colour per frame, so gradients and photographic detail that would band and dither badly in a GIF render cleanly.

The practical result for anyone actually making one: a short looping clip, a UI screen recording, a simple animated graphic, routinely comes out well under half the size of the equivalent GIF while looking noticeably cleaner, particularly anywhere the original had smooth colour transitions.

Common myths about WebP worth clearing up

'WebP is a Google-only format' isn't accurate, and hasn't been for a while. The specification is published and openly licensed, and every major browser vendor implemented support independently. It launched from Google and took root in Chrome first, the way a lot of web technology does, but that's a history, not a restriction.

'WebP always looks worse than JPG' isn't right either. Image quality in either format depends entirely on the setting used to encode it, the same way comparing two JPGs saved at different qualities would be a meaningless comparison. At matched visual quality, WebP is the smaller file, not the worse-looking one, that is the entire point of the format.

'You need special software to create WebP files' hasn't been true for a long time. Any current browser, most image editors, and plenty of phone camera apps can produce one directly, and a growing number of websites generate them automatically from whatever you originally uploaded, without you doing anything at all.

WebP on phones and inside other apps

Android has supported WebP for longer than most desktop software has. Basic decoding arrived in Android 4.0 in 2011, with full support for both lossless encoding and transparency added in 4.2.1 the following year. That means the format has been safe to assume on Android for the better part of a decade and a half, well before desktop browsers caught up.

A lot of apps you already use, messaging apps, social apps, shopping apps, save images internally as WebP for exactly the size reasons covered in this guide, without ever surfacing the file extension to you while you're using the app. You typically only encounter it directly when you export or save a file out to your device rather than while it stays inside the app.

iOS took longer to catch up on the app side specifically, even after Safari itself gained support in 2020, because individual apps have to opt in to handling the format themselves rather than inheriting it automatically from the system browser. That gap has mostly closed as app developers updated their own image-handling code, but it explains why 'my iPhone doesn't open WebP' sometimes turned out to mean one specific app rather than the phone itself.

Picking between WebP and its alternatives for a real project

Picking a format for an actual project comes down to fewer variables than all the comparisons above might suggest. If the images are ordinary photographs headed for a general audience on a platform you control, WebP is a safe default that costs nothing over JPG in compatibility terms today and saves real bandwidth on every visit, which adds up quickly at any real traffic volume.

If transparency matters and the underlying content is a photo rather than flat graphics, lossy WebP with alpha usually beats PNG outright, a smaller file carrying the same transparency, which is exactly the combination a product photo on a white background or a graphic with a soft shadow actually needs. If the content is flat graphics instead, an icon, a logo, a simple diagram, lossless WebP and PNG land close enough in size that either is a reasonable choice, and PNG's slightly wider recognition among non-technical collaborators can end up the deciding factor rather than the size difference.

The one case worth pausing on separately is archival. If a file is the only copy of something you actually care about keeping indefinitely, a family photo, original artwork, a scanned document, storing it in a lossless format rather than a lossy one costs some space now in exchange for not having already thrown detail away before you know for certain you won't need it back later.

None of this is a permanent commitment either way. Because converting between formats on this site costs nothing but a few seconds and never touches the original file, the safer general habit is to keep whatever you're not sure about in a lossless format and only commit to a lossy one, WebP included, for the specific copy you're about to publish or send somewhere.

Checking which mode a specific WebP file is using

If you're ever unsure whether a particular WebP file is lossy or lossless, and it matters, editing it further, deciding whether to convert it, most image editors and even a browser's own developer tools will show you the encoded format in the file's properties or preview panel. There isn't a reliable way to tell just by looking at the picture, since a well-encoded lossy WebP at a high quality setting can look pixel-identical to a lossless one on an ordinary screen.

As a rule of thumb, a WebP that came out of a camera app, a screenshot tool, or a web page's photo gallery is almost always lossy. A WebP that came out of a design tool exporting a logo, an icon, or line art is more likely lossless, since that's the appropriate mode for that kind of content and most tools default to it for graphics.

When it genuinely matters, the safest approach is simply to treat any WebP whose origin you don't know as lossy, and keep a separate master copy before making further edits, rather than assuming a losslessness you can't actually confirm.

Quick questions

Converters

The converter on this page handles every conversion this guide talks about.

• JPG to WebP converter
• PNG to WebP converter
• WebP to JPG converter