WebP vs JPEG: Which Format Should Your Website Actually Use?

You ran a speed test, or you pasted your homepage into a tool like imagecheck.tools, and got a nudge to serve images in a "next-gen format." Nine times out of ten that means switching JPEG files to WebP. Before you touch a single image, it helps to know what WebP vs JPEG actually comes down to: file size, compatibility, quality, and whether Google genuinely cares which one you pick. Short answer, WebP wins on size and features almost every time. Longer answer, worth the rest of this page.

Think of this as three separate layers stacked on top of each other. There's the file format itself (what the image data looks like once it's decoded). There's the delivery layer (how your server decides which format to hand a given visitor). And there's the indexing layer (what Google Images does with whatever it finds).

Most "WebP vs JPEG" confusion comes from mixing those three up, so we'll keep them separate as we go.

What Is WebP vs JPEG, Actually?

WebP is an image format Google introduced in 2010, built to do everything JPEG does and a few things it can't. JPEG only compresses photographs in a lossy way, meaning some image data is thrown away permanently to shrink the file. WebP image compression works both ways: it has a lossy mode for photos and a separate lossless mode for graphics where every pixel needs to survive intact, like a screenshot or a logo. It also supports transparency (an alpha channel, the thing that lets a PNG logo sit on a colored background without a white box around it) and simple animation, replacing what used to require an animated GIF.

JPEG can't do either of those last two things. Not "does it badly," genuinely can't. That's not a compression argument, it's a features gap, and it's one reason WebP isn't just "JPEG but smaller."

WebP vs JPEG: the core numbers

Here's where most articles on this topic stop, so we'll keep it tight and move on to the parts that actually change what you do next.

Those size figures come from Google's own WebP compression study, which matched images at equal SSIM (a technical measure of perceived visual similarity) rather than just eyeballing them. For photographic images specifically, the study also found WebP lossless files running about 1.70x smaller than PNG, which matters if you've been using PNG for photos out of habit rather than necessity.

Is WebP better than JPEG?

For most images on most websites, yes. Smaller files load faster, and faster-loading pages tend to keep visitors around longer. That part isn't controversial.

But "better" comes with two honest caveats worth knowing before you convert anything. First, if an image needs transparency, JPEG was never a fair option anyway. That's a WebP-or-PNG decision, not a WebP-vs-JPEG one.

Second, quality settings still matter more than the format itself. Site owners using the Imagify plugin on WordPress have reported visible banding (that stepped, blotchy look in smooth gradients like skies or shadows) when compression was pushed too aggressively during conversion.

That's not a flaw in WebP. It's the same mistake you'd make cranking a JPEG's quality slider too low, just showing up in a newer format. The fix is the same too: back off the compression a notch and check the result before publishing.

WebP browser support: does everyone's browser show it?

This used to be the strongest argument against WebP, and it's mostly gone stale. Current WebP browser support sits around 96 to 97 percent of global traffic according to caniuse.com's tracking data, which updates monthly. The remaining gap is almost entirely legacy iOS versions before iOS 14 and Internet Explorer, which Microsoft ended mainstream support for back in June 2022.

If that small remaining slice worries you, there's a standard, no-risk way to handle it: the HTML <picture> element, which lets a browser choose a WebP source if it understands the format and fall back to a JPEG automatically if it doesn't. MDN documents the exact markup pattern for this. Nobody sees a broken image either way. WordPress core has supported WebP upload and display natively since version 5.8 in 2021, per the official WordPress core development announcement, so if your CMS is WordPress, this isn't a plugin-dependent capability anymore.

Should you convert all your JPEGs to WebP?

This is the question nobody seems to answer directly, and it's worth a real framework instead of a flat yes or no.

• New images going up from today: yes, WebP by default. There's no reason to add fresh JPEG weight to a page when the alternative costs you nothing in compatibility.
• Old images that are already well-optimized: maybe not worth the effort. The WebP Express plugin's own documentation makes a point worth repeating: converting an already heavily-compressed, low-quality JPEG into a high-quality WebP file doesn't recover anything you lost, and can occasionally produce a larger file than converting at a matched quality setting. If an old image was compressed properly the first time, re-encoding it might be busywork. If you're not sure which images actually need the work, that's exactly the kind of question a full audit answers rather than a guess: see how to reduce image file size without losing quality for a broader framework beyond format alone.
• Images visitors need to download, print, or forward as-is: reasonable to leave as JPEG. There's a genuine, if unglamorous, friction point here: people right-clicking an image and choosing "save as" sometimes get a .webp file that older desktop software, or a print shop's upload form, won't accept. This has come up often enough in Shopify's own community forums that it's worth taking seriously rather than dismissing as an edge case.
• Images feeding an email template: keep JPEG or PNG. Email client rendering is its own inconsistent world, and it's not the hill to fight the WebP battle on.

Picture a boutique selling scarves online, a recipe blog with step-by-step food photography, and a daily news site publishing dozens of images a shift. The boutique and the blog can convert almost everything without a second thought, most of their traffic is browsing, not downloading. The news site might keep a JPEG export path specifically for images syndicated to partners or pulled by wire services that expect JPEG. Same format question, different answer, because the images do different jobs.

Does Google prefer WebP?

No, not directly, and this is worth stating plainly because a fair amount of content online implies otherwise. Google recommends WebP and AVIF for their compression efficiency, but recommended is not required, and nothing in Google's own indexing guidance states a ranking preference for one image format over another.

What actually happens is indirect, but real. Smaller image files help your Largest Contentful Paint (LCP) score, one of Google's Core Web Vitals, and Google's own page experience announcement confirms that experience signals like these feed into how it evaluates a page.

So WebP doesn't get you ranked higher for being WebP. It gets your page faster, and faster pages tend to score better on a signal Google does weigh. The format is a means, not the mechanism. If file names and alt text are also on your to-do list, our alt text guide for every image type covers the rest of what Google Images actually looks at.

A quick word on AVIF vs WebP

If you've dug into this further, you may have run into AVIF, an even newer format. Several independent compression comparisons converge on AVIF beating WebP by roughly 20 to 30 percent at matched visual quality for photographic images, though this figure comes from secondary testing rather than one controlled study, so treat it as a general direction rather than a fixed number.

Where WebP still wins is practical: broader browser support today, and noticeably faster decode times, meaning less work for a visitor's device to actually display the image. For most sites, WebP remains the safer default right now, with AVIF worth watching as support and tooling mature further.

JPEG vs PNG vs WebP: picking the right format for the job

Since these three keep getting compared together, here's a quick reference for which one actually fits each situation (the social share image is its own case, covered in the OG image size guide):

How to check and convert images on your site

If a speed test flagged you, don't convert blindly. Run the site through imagecheck.tools's image audit first and look specifically for images flagged no_modern_format, that's the tool's way of pointing at JPEG or PNG files over 60 KB that aren't being served through a responsive srcset or picture setup. That list is your actual to-do list, not every image on the domain.

One more thing worth knowing if you've re-run Lighthouse or PageSpeed Insights recently and noticed the old "Serve images in next-gen formats" line has disappeared: it hasn't gone away, it's been folded into a broader "Improve image delivery" insight that also covers compression level and responsive sizing together. The underlying advice hasn't changed, just the packaging, so don't read a differently-labeled report as a new requirement.

From there, the conversion path depends on your setup. WordPress users can rely on core support since version 5.8, or a dedicated image-optimization plugin for bulk conversion. If you're managing image delivery at the server level, serving WebP to browsers that support it while falling back to JPEG for the rest is a job for rewrite rules, which is squarely htaccess.tools territory if you're on Apache. Either path gets you to the same place: new images going up as WebP by default, old images converted where the file size actually justifies the work, and JPEG kept deliberately where a real reason exists to keep it.

Frequently Asked Questions

Is WebP better than JPEG?

For most web images, yes. WebP produces files roughly 25 to 34 percent smaller than JPEG at equivalent visual quality, and it supports transparency and animation, which JPEG cannot do at all. The main caveats are quality settings (an overly aggressive conversion can introduce banding, just as it can with JPEG) and workflows where a downloadable or print-bound JPEG genuinely serves the job better.

Do all browsers support WebP?

Not literally all, but close enough that it's rarely a practical blocker. Global support sits around 96 to 97 percent, with the remaining gap concentrated in legacy iOS versions before iOS 14 and Internet Explorer, which Microsoft ended support for in 2022. Using the HTML picture element with a JPEG fallback removes any risk of a broken image for that remaining slice.

Should I convert all my JPEGs to WebP?

Convert new images by default, since there's little downside. For your existing library, prioritize large, already-unoptimized JPEGs first, and don't bother re-encoding old images that were already compressed well. Keep JPEG deliberately for images visitors need to download, print, or forward through software that may not open a .webp file.

Does Google prefer WebP?

Google's own guidance does not state a ranking preference for WebP over JPEG or any other format; it simply recommends WebP and AVIF for their compression efficiency where a site can use them. The benefit is indirect: smaller WebP files can improve page speed metrics like Largest Contentful Paint, which is part of Core Web Vitals, a factor Google does document as part of ranking. The format itself isn't the signal, the speed it enables is.