For three decades, JPG has been the dominant image format on the web. It's widely supported, universally understood, and every tool in existence can open one. But two modern formats have now emerged that deliver dramatically better compression at the same or better visual quality: WebP, developed by Google, and AVIF, built by a coalition of the world's largest technology companies. This guide breaks down exactly how they compare so you can make the right format choice for your website.
WebP was developed by Google and first announced in 2010, built on compression technology derived from their VP8 video codec. It's a completely open format, free to use, and was designed from the ground up to replace both JPG (for photographic images) and PNG (for images requiring transparency) with a single, more efficient alternative.
WebP supports both lossy and lossless compression modes. In lossy mode it applies psycho-visual compression — techniques that exploit how the human visual system works — to produce files 25–35% smaller than an equivalent-quality JPG. In lossless mode it encodes images with zero quality loss while still beating PNG on file size, typically by 15–20%.
Beyond compression, WebP offers several capabilities that JPG simply cannot match: a full 8-bit alpha channel for transparency, animation support (similar to animated GIF but far more efficient), and metadata handling for EXIF and XMP data. These make WebP a genuine all-in-one format that covers the vast majority of web image use cases.
Browser support is now essentially universal. Chrome has supported WebP since 2014, Firefox since 2019, Edge since 2018, and — after years as a holdout — Apple added WebP support to Safari 14 in late 2020. In 2026, WebP is safe to use without any fallback in any context where you control the delivery environment.
AVIF (AV1 Image File Format) is a significantly newer format, standardized in 2019 and gaining mainstream browser support through the early 2020s. It's derived from the AV1 video codec, which was developed collaboratively by the Alliance for Open Media — a consortium that includes Apple, Google, Netflix, Mozilla, Microsoft, Amazon, Intel, and AMD. That level of shared engineering investment means AVIF benefits from extraordinary optimization effort and carries no patent licensing fees, making it genuinely free to implement and use.
The compression improvements in AVIF are substantial. Compared to JPG at equivalent visual quality, AVIF typically produces files 30–50% smaller — a meaningful step beyond WebP's 25–35% advantage. At aggressive quality settings, where JPG and WebP start to show blocky 8×8 pixel artefacts, AVIF degrades more gracefully, producing softer blurring rather than harsh blocking. This means you can push AVIF further before quality becomes unacceptable.
AVIF also supports a much wider colour gamut than JPG, including HDR (High Dynamic Range) content and up to 12-bit colour depth, compared to JPG's 8-bit limit. For most web use cases this is not a practical differentiator today, but it matters for high-fidelity photography and content intended for modern HDR displays. Like WebP, AVIF supports both lossy and lossless compression, full alpha channel transparency, and animation.
To make the comparison concrete, here's what typically happens to a 1 MB JPG photograph when converted to each format at comparable visual quality settings:
These percentages vary by image content. Photographs with smooth gradients, soft lighting, and natural textures tend to show larger AVIF advantages. Images with sharp geometric edges or fine text detail may show smaller differences. At very aggressive compression settings — where you're deliberately pushing for the smallest possible file — the gap widens further in AVIF's favour, because AVIF maintains acceptable quality at lower quality levels than WebP.
For a website serving hundreds or thousands of images, switching from well-optimised JPG to AVIF can reduce total image bandwidth by 40–50%. That translates directly to faster page loads, lower hosting and CDN costs, and meaningfully better Core Web Vitals scores — all of which have direct implications for search rankings.
Real-world impact: A typical e-commerce product page with 8 images averaging 200 KB each (in JPG) becomes approximately 820 KB with WebP and around 640 KB with AVIF. At scale, these savings compound into millions of gigabytes of bandwidth reduction per year.
Browser compatibility has historically been the biggest barrier to adopting newer formats. By 2026, the picture has changed substantially for both WebP and AVIF.
WebP now has near-universal support across all modern browsers and platforms. Chrome supported it from version 32 onward, Firefox from version 65, Edge from version 18, and Safari from version 14. Coverage is effectively 100% of modern browsers. The only situations where WebP isn't safe to assume are legacy environments like older email clients, some PDF generators, and very old mobile browsers — scenarios that represent a small and shrinking fraction of real traffic.
AVIF is not quite universal but is approaching it. Chrome has supported AVIF since version 85 (August 2020), Firefox since version 93 (October 2021), Safari since version 16 (September 2022), and Edge since version 121 (early 2024). Global browser coverage sits around 95% of web users. The remaining 5% are primarily legacy browsers, older iOS devices that haven't updated, and some Android WebView implementations.
The practical solution for that 5% is the HTML <picture> element, which lets you specify a list of sources in preferred order and fall back gracefully:
AVIF with fallback: <picture><source srcset="img.avif" type="image/avif"><source srcset="img.webp" type="image/webp"><img src="img.jpg" alt="Description" width="800" height="600"></picture>
Browsers try each <source> in order and use the first format they can decode. This approach delivers AVIF to modern browsers, WebP to slightly older ones, and JPG as the universal last resort — all from a single HTML block with no JavaScript required.
At high quality settings — above roughly quality 85 on a 1–100 scale — the visual difference between WebP and AVIF is minimal and essentially impossible to detect at normal viewing sizes on standard displays. Both formats produce excellent results for typical web publishing at these settings.
The differences become meaningful at lower quality settings, which is where file size savings start to compound. Below quality 70, AVIF holds up significantly better. While JPG and WebP produce the characteristic blocky 8×8 pixel artefacts and colour banding that signal heavy compression, AVIF tends to produce subtle blurring that is less visually jarring. For content where you're targeting very small file sizes — mobile-optimised thumbnails, low-bandwidth serving — AVIF is the clearly better choice at any given file size target.
For animations, WebP currently holds a practical advantage. Animated WebP is well-supported by encoding tools, and browsers handle it consistently. AVIF does support animation through the AVIS container format, but tooling support is less mature, and not all browsers handle AVIF animations identically. If you need animated web images in 2026, WebP (or a short MP4 video with autoplay, muted, and loop attributes) remains the more reliable choice.
One important practical consideration that rarely comes up in format comparisons is encoding speed — how long it takes a server or tool to generate the compressed file from the source image.
WebP encoding is fast. A typical image compresses in a few milliseconds using the libwebp library, and real-time WebP conversion is entirely feasible on modest server hardware. This makes WebP well-suited for image pipelines that generate files dynamically, such as an e-commerce platform serving product photos in multiple sizes, or a CMS resizing user-uploaded images on the fly.
AVIF encoding is significantly slower — often 5–15 times slower than WebP, and sometimes more for complex images at high quality settings. Encoding an AVIF in real time, per request, is generally impractical on most server configurations. AVIF works best for static assets that are compressed once and served many times, or for batch-processing pipelines that run ahead of time and cache the results.
The encoding speed gap is narrowing as hardware encoders mature and libraries like libaom and libavif are optimised further. But as of 2026, it remains a meaningful constraint for dynamic image-serving architectures that need to encode at request time.
Given everything above, here's a practical decision guide for common use cases:
<picture>. You get maximum compression for 95% of visitors with zero quality risk for the rest.Converting your existing JPG and PNG images to WebP is straightforward using InkTools' free WebP converter. It runs entirely in your browser — no files are uploaded to a server, no account is required, and there's no file size limit imposed by a server queue. You can convert images individually or in batches, and adjust the quality setting to dial in your preferred balance between file size and visual quality.
For AVIF conversion, browser-based tools are still catching up, but command-line tools like avifenc (part of the libavif library) and Google's Squoosh web app both support AVIF encoding with configurable quality settings. Build tools like Vite, Next.js, and webpack have plugins that can automatically generate AVIF versions of your images as part of your build pipeline.
Whichever format you choose, the workflow is the same: start with the highest-quality source file you have, resize to the maximum display dimensions you'll use, convert to your target format, then compress to your target quality. Never compress an already-compressed image if you can avoid it — always work from the original.
<picture> element, with a WebP or JPG fallback for the remaining browsers. This gives you the compression benefits of AVIF for the vast majority of visitors with no quality penalty for the rest.<picture> element with multiple <source> tags in order of preference: <picture><source srcset="image.avif" type="image/avif"><source srcset="image.webp" type="image/webp"><img src="image.jpg" alt="Description" width="800" height="600"></picture>. The browser picks the first format it supports. Always include a standard <img> tag as the final fallback — it handles browsers that don't support the <picture> element at all, and is required for accessibility.Convert your JPG and PNG images to WebP free — no upload required, no account needed.
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