Google PageSpeed Insights called out your images. You've seen the warning: "serve images in next-gen formats." Your photos look sharp, your visitors aren't complaining, but the report says your page is slow — and the culprit is almost always JPEGs and PNGs sitting there like it's 2009. WebP is the format Google keeps pushing you toward, and the reasons are concrete and measurable. This article covers what WebP actually is, why the compression numbers matter, when it's the right call, and when it genuinely isn't. If you want to skip straight to converting, ConvertSnap.in is a free browser-based tool you can open right now — no account, no file uploads, nothing leaving your device.
What Is WebP, Exactly?
WebP is an image format developed by Google and released in 2010, built on top of the VP8 video codec — the same technology that compresses video frames — which explains why it achieves such dramatic file size reductions compared to formats designed decades earlier. The goal was blunt: replace JPEG, PNG, and GIF for web use with a single format that beats all three.
What makes WebP genuinely unusual is the range of what it handles. It supports lossy compression, lossless compression, transparency through a full alpha channel, and animation. No other image format in widespread web use covers all four simultaneously. JPEG is lossy only and has zero transparency support. PNG is lossless but can't animate. GIF animates and has a rudimentary form of transparency, but uses compression so old that it produces enormous files by any modern standard. WebP does all of it. That's not a minor footnote — it's a structural advantage if you want to simplify your image workflow instead of managing three different format types across your site.
One thing worth knowing if you work with large source files: WebP supports a maximum image dimension of 16,383 by 16,383 pixels. More than enough for web use, and sufficient for most photography workflows, but good to know before you run into it unexpectedly.
Lossy vs. Lossless WebP — What's the Difference?
When you convert an image to WebP, you pick one of two modes. The choice takes about five seconds once you understand the difference.
Lossy WebP works like JPEG compression. It analyzes the image, discards visual data your eye is unlikely to notice, and produces a smaller file at the cost of some quality. At compression levels between 75 and 85 — the standard sweet spot for web use — the quality loss is typically invisible. Lossy WebP is the right choice for photographs, hero images, product shots, and anything where a small, imperceptible trade-off in quality is acceptable. Lossless WebP preserves every pixel exactly. Files are larger than lossy WebP, but still approximately 26 percent smaller than a comparable PNG. Use it for logos, icons, illustrations, screenshots, and any image where crisp edges, flat colors, or full transparency without degradation actually matter.
One-line rule: If it's a photograph, use lossy WebP. If it's a graphic with sharp edges, flat color, or transparency, use lossless WebP.
WebP vs. JPEG vs. PNG — The Numbers
The case for WebP comes down to file size, and the numbers are specific enough to be useful rather than vague.
According to Google's original WebP research — replicated by independent benchmarking tools including Squoosh and web.dev — lossy WebP files are 25 to 34 percent smaller than JPEG files at equivalent visual quality. Lossless WebP files are approximately 26 percent smaller than PNG. These aren't marginal gains. On a page with ten product images, switching from JPEG to lossy WebP cuts total image payload by roughly a third.
Here's how the common formats compare across the capabilities that matter most for web publishing:
JPEG supports lossy compression only, has no transparency, and no animation support. Files are typically about 30 percent larger than an equivalent WebP.
PNG is lossless only, supports full transparency, but cannot animate. Files are typically about 26 percent larger than an equivalent WebP.
GIF is lossless and supports animation and 1-bit transparency — meaning pixels are either fully transparent or fully opaque, with no partial transparency. For animated content, GIF files are often several times larger than WebP.
WebP supports lossy compression, lossless compression, full alpha channel transparency, and animation. This is the baseline everything else is measured against.
The key point: WebP is the only format in widespread web use that covers all four capabilities — lossy, lossless, transparency, and animation — simultaneously. If you currently use JPEG for photos, PNG for graphics, and GIF for animations, WebP can replace all three with smaller files across every category.
Browser Support in 2025
Yes, it's safe to use. That answer deserves to come first because browser support anxiety is the most common reason people still hesitate on WebP.
As of 2025, WebP is supported by approximately 97 to 98 percent of browsers in active use, according to caniuse.com. The holdouts are Internet Explorer — which reached end-of-life in 2022 and now represents a negligible slice of real traffic — and a small tail of outdated Android WebViews on devices that haven't received a software update in years. For any general-audience website in 2025, you can use WebP as your primary image format without building a fallback strategy. The fraction of visitors who can't render WebP is so small it falls below what most analytics teams would bother to flag.
Bottom line: If you're building for the modern web — not legacy IE — you can switch to WebP today without a fallback strategy. The browser compatibility concern that existed in 2018 is no longer a practical obstacle.
If you're running an internal enterprise tool with known Internet Explorer requirements, that's a different conversation. But for a blog, e-commerce store, portfolio, or marketing site, WebP is safe to deploy right now. Ready to convert your first image? Try ConvertSnap.in free — no sign-up, no upload →
How WebP Affects Your Core Web Vitals
Page speed affects rankings, not just user experience. Google uses Core Web Vitals as part of its page experience ranking signals, and the most important metric for image-heavy pages is Largest Contentful Paint — LCP. It measures how long it takes for the largest visible element on a page to fully load. For most websites, that element is a hero image or banner.
What LCP Actually Means for Your Rankings
LCP is a direct line between your image format choices and your position in search results. Google's guidance is that LCP should occur within 2.5 seconds from when the page starts loading. Images that are 25 to 34 percent smaller load proportionally faster on slower connections, which is exactly where LCP scores fall apart most often. You don't need deep technical knowledge to act on this — switching the format of your heaviest images is frequently sufficient to move LCP from the "Needs Improvement" band into the "Good" band.
Switching image formats is one of the lowest-effort, highest-impact changes available for improving Core Web Vitals — no developer, no plugin, no paid tool required.
When NOT to Use WebP
Every article about WebP is enthusiastic about it. That enthusiasm is earned, but no format is right for every situation. Here's where WebP genuinely doesn't belong.
Email clients don't support WebP. Full stop. If you're designing images for newsletters or transactional emails, stay with JPEG or PNG. Gmail, Outlook, and Apple Mail all handle those reliably. WebP images in email will either not display or will show as broken placeholders — not a good look for a campaign you spent time building.
Some older content management systems have patchy WebP support. WordPress added native WebP support in version 5.8, released in 2021. Older installations without updates, and some legacy Drupal or Joomla setups, may reject WebP uploads based on MIME type validation. A plugin usually resolves this, but it's worth checking before converting your entire image library and discovering the uploads are blocked.
Print workflows don't use WebP at all. It's a web delivery format, not a print format. Design software and prepress tools won't recognize it. If your images are headed to printed materials, PDFs for distribution, or a commercial printer, keep working in TIFF, PNG, or high-quality JPEG.
Social media platforms re-compress whatever you upload regardless of format. Instagram and Facebook transcode images on their own servers before displaying them. For social media assets, JPEG or PNG is the practical choice — uploading WebP provides no real advantage when the platform is going to reprocess the file anyway.
The reframe: None of this is a reason to avoid WebP — it's a reason to understand where it belongs. Web publishing — product images, blog photos, hero banners, portfolio thumbnails — that's its home. For email, print, and social uploads, keep JPEG and PNG in your toolkit.
WebP vs. AVIF — Which Should You Actually Use?
AVIF is the format some developers are already experimenting with, and it genuinely achieves better compression than WebP. Independent benchmarks show AVIF producing files 20 to 50 percent smaller than WebP at comparable visual quality. If pure compression efficiency is the only metric, AVIF wins.
The practical situation in 2025 is more complicated. AVIF encoding is significantly slower than WebP encoding, which matters a lot when you're converting hundreds of images in a batch. Tooling support is less mature, CMS compatibility is patchier, and browser support — while good — isn't as consistent as WebP's 97 to 98 percent coverage. For a site running WordPress, Shopify, or Squarespace, WebP is the reliable, well-supported choice for everyday conversion work. AVIF is worth watching and worth testing on individual high-priority assets, but it's not a practical wholesale replacement for WebP in typical workflows yet.
The honest take: If you're converting a library of images and want the best balance of file size, quality, and compatibility right now, WebP is the answer. Revisit AVIF in a year or two as the ecosystem matures.
Why Converting in the Browser Matters More Than You'd Think
If you're uploading your images to a random conversion website, stop and think about what you're actually doing.
Most free image converters ask you to upload your file to their server, process it remotely, and let you download the result. For stock images or placeholder graphics, that probably feels harmless. For anyone working with client photos, unreleased campaign assets, or anything covered by an NDA, uploading those files to an unknown third-party server is a genuine risk — one that most people don't think about until something goes wrong.
ConvertSnap.in works differently. Conversion happens entirely in your browser using the Canvas API, a built-in browser technology that reads and re-encodes image data locally. Your images never leave your device. There's no upload step, no server receiving your files, nothing stored on anyone else's system. The conversion runs on your computer and the output file goes directly to your downloads folder.
How to convert using ConvertSnap.in right now: open the site — no account, no sign-in required. Drop your image or images onto the conversion area, or click to select files from your device. Choose WebP as your output format. Select lossy for photographs, lossless for graphics, logos, or images with transparency. Click convert. Your WebP file downloads immediately to your device. Replace the original in your website's media library and republish. The whole process typically takes under a minute per image, and you can drop multiple files at once to convert a batch.
Start Using WebP Today
WebP is not experimental. It's not a niche choice for developers who enjoy reading format specifications at 2am. It's a mature, widely supported format with a decade of real-world deployment behind it. The file size reductions are real and measurable, browser support is as close to universal as any format gets, and the Core Web Vitals benefits are well documented.
The honest reason most websites are still serving JPEGs and PNGs is inertia. Nobody stopped to make the switch. That switch takes less time than reading this article took. Head to ConvertSnap.in, drop in your images, and download your WebP files. No account, no upload, no waiting. Your images stay on your device the entire time. It's the fastest way to start delivering lighter, faster images to everyone who visits your site — and your PageSpeed score will have a lot less to complain about.