WebP vs JPG vs AVIF: Which Image Format? (2026 Guide)

Every photo you have ever uploaded to a website, sent over email, or embedded in a PDF was almost certainly a JPEG. The format turned 34 years old this year, and it is still the default everywhere, on cameras, on social media, on every stock photo site on the internet. But two newer formats now beat JPEG on both file size and visual quality by a wide margin. So why has nothing changed?

The answer is boring: support. For years, only one browser supported WebP and AVIF was still a research project. That is no longer true. In 2026, WebP works everywhere and AVIF works almost everywhere. The excuse for shipping 400 KB JPEGs is gone.

This guide covers what actually matters when you are picking a format in the real world: size on disk, quality at a given size, browser support, and a simple rule for choosing the right one.

The three formats, in one paragraph each

Before the comparison, a quick honest introduction to each.

JPEG: the 1992 default

JPEG was designed for photographs in an era when a 1 MB image was considered large. It uses a mathematical technique called the discrete cosine transform to throw away detail the human eye is unlikely to notice. The result is a small file with acceptable quality, and the reason it won is that everything supports it. Every camera writes JPEG. Every browser displays it. Every printer, every server, every piece of software in the world understands it.

The downside is that JPEG quality degrades quickly once you push compression. Below 70 percent quality, you start seeing 8x8 pixel blocks around sharp edges and colour fringing on high-contrast lines. It has no transparency, no animation, and no support for wide colour gamuts or HDR.

WebP: Google's quiet replacement

WebP was released by Google in 2010 as part of the VP8 video codec project. It supports both lossy and lossless compression, plus transparency and animation, a combination JPEG and PNG each lacked. At typical photo quality, WebP files are 25 to 35 percent smaller than JPEG at the same visual quality.

For years, WebP was Chrome-only. Safari and Firefox only adopted it in 2020 and 2021. That is why it took a decade for WebP to become safe to use. As of 2026, every browser in active use supports it, including iOS Safari and Chrome on Android.

AVIF: the state of the art

AVIF is built on the AV1 video codec, developed by the Alliance for Open Media (Google, Netflix, Amazon, Apple, Mozilla and others). It reached formal publication in 2019 and started shipping in browsers in 2021 and 2023. AVIF files are typically 20 to 40 percent smaller than WebP at the same quality, which means they are often 50 percent smaller than JPEG.

AVIF also supports HDR, wide colour gamuts, transparency, animation and even sequences of frames with depth information. It is genuinely the most capable consumer image format ever deployed. The catch is encoding cost. AVIF files take longer to generate than JPEG or WebP, which matters on servers but not on personal devices.

Real size comparison: same photo, three formats

Here is the same 4000 x 3000 photograph of a landscape, encoded in each format at comparable visual quality. These are the kind of numbers you will see in practice:

Two things to notice. First, AVIF at "quality 50" is not worse than JPEG at "quality 85". The quality scales are not comparable across formats. AVIF's 50 looks like JPEG's 85. Second, PNG is enormous for photographs. It is the right format for screenshots and logos, not photos.

Browser support in 2026

This is where the real decision gets made. A format that nobody can display is worthless, no matter how efficient.

WebP has been safe to use in production for about four years. AVIF became safe in late 2023 when Safari 16 shipped support. That was the last holdout. If your audience is on modern phones and browsers (which most are), AVIF is now usable without a fallback.

HEIC, the format iPhones write by default, is still not supported in Chrome or Firefox. That is why you constantly see iPhone photos that will not open on Windows. If you are preparing iPhone photos for the web, they need to be converted first.

When to use which format

A simple rule, broken down by what the image actually is.

For photographs on the web: WebP or AVIF

If your image is a photograph of the real world, people, landscapes, products, food, use WebP or AVIF. Both beat JPEG on size at the same quality. If you care about the last 20 percent of size, use AVIF. If you want maximum compatibility with the smallest amount of fuss, use WebP.

In practice, many modern sites serve both: AVIF to browsers that support it, WebP to the rest, JPEG only as a last resort. This is done with the <picture> element and takes about ten lines of HTML.

For screenshots, UI, logos and diagrams: PNG

If the image has flat colours, sharp edges and text, PNG is still the best choice. It is lossless, which means edges stay razor-sharp. It supports transparency, which matters for logos and UI. And for screenshots of apps or websites, PNG files are often smaller than JPEG because JPEG wastes bits trying to preserve sharp edges it cannot compress.

For simple logos and icons, SVG is even better. It is a vector format, resolution-independent, and often just a few hundred bytes.

For images with transparency: WebP or PNG

WebP supports transparency and is typically 30 to 50 percent smaller than PNG for the same transparent image. If you are on a budget for file size and the image is not too detailed, WebP is the modern choice. If you need maximum compatibility (like an old email client), PNG is safer.

For animations and GIFs: WebP or MP4

The GIF format is 1987 technology and should have died years ago. A short animated GIF that weighs 8 MB becomes a 400 KB WebP and a 250 KB MP4. Both play in modern browsers. If you still see GIFs on your site or in your docs, converting them to WebP or MP4 is one of the biggest easy performance wins available.

For archival storage: PNG or original RAW

If you are keeping photos forever and do not care about size, use PNG (lossless) or keep the original camera RAW file. JPEG, WebP and AVIF are all lossy. Each time you open and re-save one, you lose a little more quality. For a photo you will edit dozens of times, you want lossless.

How to convert between formats

The most reliable way to convert without uploading your files anywhere is a browser-based converter. It runs on your device, supports every common format, and does not hand your photos to a stranger's server.

1. Open the Image Converter tool.
2. Drop your files in. JPG, PNG, WebP, AVIF, HEIC, GIF, TIFF, BMP, SVG and more are all accepted.
3. Pick the output format. For web photos, choose WebP or AVIF. For screenshots and logos, choose PNG.
4. Set the quality slider if the format supports it. 80 to 85 for JPEG, 50 to 60 for AVIF (yes, the numbers are on different scales).
5. Download the converted files.

If you run a website, here is what to actually do

The single biggest performance win most sites miss is serving modern image formats. Here is the practical checklist:

• Convert your 10 largest JPEGs to WebP. That alone will usually cut page weight by 30 percent.
• Add a picture element with AVIF, WebP and JPEG sources. The browser picks the best it supports.
• Compress every remaining image to remove metadata and reduce quality to the smallest acceptable level.
• Replace any GIF on the page with WebP or MP4. GIFs are usually the worst offenders on content-heavy pages.
• Add width and height attributes to every img tag to prevent layout shift as images load.

What about HEIC?

Every iPhone since 2017 writes HEIC photos by default. HEIC is a container format that uses HEVC compression. It is roughly as efficient as AVIF, but it is patented and requires a licence to decode. That is why Chrome and Firefox refuse to support it and why Windows 10 needed a free extension to open them.

If you are preparing iPhone photos for the web, you have two options: convert HEIC to JPG (safe and universal) or convert HEIC directly to WebP or AVIF (smaller, but the converter has to decode HEIC first). Either works. Just do not leave them as HEIC. Half your visitors will not be able to see them.

Three myths worth clearing up

• Myth: "WebP is not supported widely enough." Reality: every browser in active use has supported WebP since 2021. This was true in 2015. It is not true now.
• Myth: "AVIF is too slow to encode." Reality: AVIF encoding takes longer than JPEG, but only on the server or on your device. Once the file exists, decoding on the client is fast. The time is measured in milliseconds, not seconds.
• Myth: "You need to pick one format." Reality: the picture element lets you serve AVIF, WebP and JPEG simultaneously. Every browser gets the best format it supports, and nobody gets a broken image.

The bottom line

If you take one thing away: JPEG is no longer the right default for photographs. WebP is universally supported and 30 percent smaller. AVIF is nearly universal and often 50 percent smaller. Both are better than JPEG in every measurable way that matters.

The only reason to keep using JPEG in 2026 is when you genuinely cannot control the format: a form that only accepts JPEG uploads, a printer that requires it, or an email attachment to someone on a very old device. Everywhere else, move on.

The image format war is over. WebP and AVIF won. Everyone just keeps shipping JPEG because nobody bothered to switch.

Common sentiment in web performance circles, 2024 to 2026