What Is AVIF? The AV1 Image Format, Measured

AVIF is the AV1 Image File Format, an open and royalty free image format that packs AV1 video codec data into a HEIF container. On a photograph it lands roughly 50 percent smaller than JPEG at the same visible quality, and it carries transparency, animation, HDR, and higher color depth than JPEG or PNG can. That, in one sentence, is what is AVIF, and the rest of this page is the byte level detail behind the claim.

Most people meet AVIF as the newest row in a compressor's output menu, one line under WebP. I run all four formats, JPG, PNG, WebP, and AVIF, through the compression engine behind imagecompressor.tools, and for a photo AVIF is reliably the smallest file of the four, at the cost of a slower encode. This page is the deep dive from the WebP and AVIF hub: where AVIF came from, what a .avif file actually is, how much smaller it really runs, how to open one, and the two limitations worth knowing before you switch everything over.

So, what is AVIF exactly?

AVIF is a still image saved with the AV1 video codec and stored in a HEIF container, standardized by the Alliance for Open Media. It is a picture compressed with the same math that shrinks streaming video, which is why it beats every image format that came before it on file size for photographs.

AV1, the codec that does the compression

AV1 is the part doing the actual work. It is a coding format built first for video transmission over the internet, and AVIF borrows a single key frame from that video codec and saves it as one still image. Video codecs spend enormous effort predicting one part of a frame from another and discarding the redundancy, and AVIF inherits all of that cleverness for a single picture. A JPEG encoder from the early 1990s has far fewer tricks available to it. That inheritance is the whole reason a modern video codec turned into one of the most efficient image formats on the web, rather than a from scratch invention that had to prove itself against decades of JPEG tuning.

HEIF, the container that holds it

The container is a separate thing from the codec, and mixing the two up causes half the confusion around AVIF. AV1 is the compression method; HEIF, the High Efficiency Image File Format, is the wrapper that holds the encoded pixels plus metadata like color profile and orientation. MDN describes AVIF as AV1 bitstreams encoded into the HEIF container, which is exactly the recipe: AV1 image data poured into a HEIF file, then given the .avif extension. HEIC, the format your iPhone saves photos in, uses the same HEIF container with a different codec inside, which is why the two names look alike but are not interchangeable.

Why open and royalty free matters

AVIF is open source and royalty free, developed under the Alliance for Open Media, and that licensing choice is a feature, not a footnote. The Alliance is a group whose members include the browser makers themselves, so the format arrives without the patent tolls that sank earlier efforts. Some genuinely good high efficiency codecs never became a web standard precisely because they shipped with licensing that scared vendors off. AVIF has no toll booth, and that is a direct reason Chrome, Firefox, and Safari all built support for it rather than waiting for someone else to go first.

Is AVIF a real image format, or just a video frame?

AVIF is a real, registered image format with its own file extension and specification, not a hack. The confusion is understandable, because underneath it genuinely is a single frame from a video codec, and people who follow codecs argue about whether that counts as a true image format.

The practical answer is that the distinction does not matter to you. A .avif file behaves like any other image: it has a header, a defined structure, a MIME type that browsers recognize, and software that reads and writes it. That it reuses AV1 rather than inventing new compression math is an engineering shortcut, and a smart one, not a sign the format is somehow less legitimate than JPEG or PNG. The only place the video heritage leaks through is in the encode time, which is heavier than a purpose built image encoder would be, and that is the tradeoff you accept for the compression it buys.

What is an AVIF file made of, and what is it used for?

A .avif file is a single AV1 encoded image inside a HEIF container, and it is used anywhere a smaller file with modern image features helps: web pages, photo galleries, HDR photography, and application assets. The extension you see on disk, .avif, is just the label on that HEIF plus AV1 package.

The .avif file extension

When you save or download one, it arrives as name.avif, and your operating system treats it as an image the same way it treats .jpg or .png, provided the software knows the format. The bytes inside are not a new kind of raw data; they are AV1 compressed image data with a header the HEIF container defines. That is why a program that has never heard of AVIF refuses the file rather than showing garbage: it reads the container, does not recognize the AV1 payload, and stops cold. Knowing what is an avif file at this level makes the compatibility quirks later on the page feel predictable instead of random.

What is AVIF used for

AVIF is used mostly to make images on the web smaller without making them look worse, and increasingly for HDR and wide color gamut photography that older formats cannot represent at all. On a website, serving AVIF instead of JPEG cuts the bytes a visitor downloads by roughly half, which is real page speed and real bandwidth saved on every single load. For photographers, the higher color support means skies and gradients that would band into visible steps in an 8 bit JPEG stay smooth. Anywhere the file leaves your control, though, JPEG and PNG are still the safe currency, because you cannot assume the other end reads AVIF, and a smaller file nobody can open is worth less than a larger one that works everywhere. A concrete case makes the scale obvious: a product gallery of 40 photos served as JPEG at 900 KB each is about 36 MB a visitor pulls down, while the same gallery as AVIF near 450 KB each is about 18 MB, half the data for the identical pictures. Multiply that across every visit and AVIF becomes a bandwidth decision as much as a quality one.

Transparency, color depth, HDR, and animation

AVIF combines features that no single older format offered all at once. It supports a full alpha channel for transparency, the same capability PNG and WebP have, so a logo or product cutout keeps its transparent background without falling back to a heavier PNG. It reads 8, 10, and 12 bit color, past JPEG's fixed 8 bit ceiling, which is what makes HDR and wide color gamut possible. web.dev reports that AVIF adds High Dynamic Range, wide color gamut, film grain synthesis, and progressive decoding to the codec, alongside savings greater than 50 percent versus JPEG in its own testing. And it animates, carrying multiple frames like a GIF or an animated WebP, in far less space than either one needs.

How much smaller is an AVIF file than JPEG, WebP, and PNG?

AVIF usually runs about 50 percent smaller than a JPEG at the same visible quality, a little smaller than WebP, and dramatically smaller than PNG for photographs. To make that concrete, here is the reference photo used across this site carried across all three modern formats using the size rules the tool is built on.

The reference file is a 4.5 MB photo straight off a phone. Compressed to JPEG at quality 80, the default treated as visually lossless, it comes back around 900 KB. WebP typically runs 25 to 35 percent smaller than that JPEG, which puts it near 630 KB, and AVIF's roughly 50 percent advantage over JPEG puts it near 450 KB for the same picture. These are derived from the size rules measured on this tool, not a fresh AVIF specific lab test, and your own photo will vary with its content, but the ranking holds every time: AVIF smallest, then WebP, then JPEG, with PNG far off the scale for a photograph.

Same visible quality is the phrase that makes this a fair fight. It is easy to make any format smaller by throwing away more detail, so a size comparison only means something when the two files look the same to your eye. That is what quality 80 anchors here: a setting tuned to sit at the edge of visually lossless for a photograph, applied consistently across the formats. The gap is also why an image CDN that serves one hero photo millions of times will happily pay AVIF's slower encode once. If you want the real number on your own file instead of a rule of thumb, drop a JPG or PNG into the AVIF compressor and read the byte count it hands back.

PNG deserves its own note here, because the table makes it look absent. PNG is lossless, meaning it discards nothing, so for a photograph it is usually larger than the original JPEG rather than smaller, and comparing it to AVIF on a photo is not a fair contest. PNG earns its place on flat graphics, screenshots, logos, and anything with sharp edges or hard transparency, where keeping every pixel exact is the point. AVIF competes with PNG on that ground through features rather than raw photographic compression. For an actual photo, PNG is the wrong tool, and AVIF against PNG is a rout that was never close.

Which browsers and apps support AVIF in 2026?

Every major current browser reads AVIF: Chrome, Firefox, Safari, and Edge, plus Opera. The one piece of recent history worth remembering is that Edge only reached support at version 121, later than the other three.

According to Can I use's AVIF support data, Chrome has supported AVIF since version 85, Firefox since 93, and Safari fully from 16.4 with partial support across 16.1 to 16.3, including Safari on iOS 16 and later. Edge trailed until version 121. In practice that means the overwhelming majority of live browsers render AVIF today, but overwhelming majority is not the same as everybody. Embedded webviews, pinned corporate browser builds, and older devices still exist, which is why the recommendation about fallbacks below is caution rather than paranoia. Opera rides on the same engine as Chrome, so its AVIF support tracks Chrome's closely, and mobile Chrome and mobile Safari follow their desktop counterparts rather than lagging behind them.

Why you still serve a fallback

MDN still recommends serving AVIF through a <picture> element that falls back to WebP, JPEG, or PNG, because AVIF's support, broad as it is now, has little historical depth. The pattern costs nothing at delivery: the browser picks the first source it understands, so a current Chrome gets the tiny AVIF and an ancient browser quietly gets the JPEG instead. You lose nothing by including the fallback, and you avoid a blank image on the one visitor whose setup has not caught up yet. On a static site this is a few extra lines in the markup, and most build tools generate the variants for you.

How do you open an AVIF file on any device?

The fastest way to open a .avif file is to drag it into any current web browser tab, which renders it instantly. If a specific app refuses the file, converting it to JPG or PNG takes seconds and removes the compatibility problem entirely.

How to open an AVIF file

Browsers are the universal answer because AVIF was built for the web first, and every current one ships with a decoder. Desktop image viewers and older editing software are the unreliable part: some read AVIF, many still do not, and there is no way to tell by looking at the file. When a program refuses it, do not fight the software. Run the .avif through a compressor set to output JPG or PNG and you get a file every program on earth opens, which is usually faster than hunting for a plugin that may not exist. This is the same reason knowing how to open an avif file matters less in practice than knowing you can always convert one in a pinch.

What are AVIF's real limitations?

AVIF's two real costs are a slower, heavier encode and a thinner software ecosystem than JPEG or WebP. A long running debate over progressive rendering is the third wrinkle, though its practical impact on a reader is small.

Slower encoding

Encoding to AVIF demands real computer time, noticeably more than encoding the same image to WebP, per Cloudinary's format comparison. Compress one photo by hand and you never notice. Run a batch job that converts thousands of images on a server and the difference becomes a line item in your compute bill. This is why AVIF fits publish once, serve forever pipelines better than it fits real time upload processing, where the encode has to finish while a user waits at the other end of a spinner. As a rough feel, an AVIF encode can take several times as long as the same image encoded to WebP at comparable quality, which is invisible for one file and genuinely painful across a hundred thousand of them.

A thinner ecosystem

Fewer programs read and write AVIF than read WebP, and far fewer than read JPEG. Design tools, older content systems, and plenty of desktop apps still treat AVIF as exotic. Handing an AVIF file to the wrong software is a real risk in a way handing over a JPEG never is, and it is the single biggest reason to keep AVIF for images you control end to end rather than files you email or upload somewhere else. The format is not the problem; the software on the far side is, and that software updates slowly.

The progressive rendering question

Here the sources disagree, and honesty means saying so. MDN states that AVIF does not support progressive rendering, so a file must download fully before it displays, unlike a progressive JPEG that paints a rough preview early. web.dev lists progressive decoding as a supported AVIF feature instead. Treat the final status as evolving rather than settled. In real use the impact is usually minor, because an AVIF file is already smaller than the JPEG it replaced and finishes downloading sooner regardless of whether it paints in stages on the way in.

When should you use AVIF instead of WebP or JPEG?

Use AVIF when you control the whole delivery pipeline and the smallest possible file matters more than encode time. Stick with WebP or JPEG when compatibility or a fast encode matters more, and never assume AVIF for a file you hand to someone else.

The clean decision is about who touches the file after you. A site you own can encode a hero image once, cache the AVIF, and serve it forever, so the slow encode is a one time cost paid back by every fast download afterward. HDR and wide color gamut photography is AVIF's clearest win, because JPEG cannot represent that color range at all. My own default is WebP for general web images and AVIF for the hero shots and galleries where the extra saving is worth the encode, which keeps build times sane while still capturing most of the bandwidth win. But an upload form, an office document, or an email attachment still expects JPEG or PNG far more reliably, and there AVIF's size advantage is worth nothing if the other end cannot open it. If you are weighing it specifically against the other modern format, the full head to head lives in AVIF vs WebP, and if you have already decided and just want the file, converting an image to AVIF takes one drag and drop. For the format one step back in the timeline, what a WebP file is covers the ground AVIF built on.

Frequently asked questions about AVIF

How do I convert an AVIF to JPEG?

Drop the .avif file into an image compressor set to output JPG, and it returns a standard JPEG in a second or two. That is also the fix when a program refuses to open an AVIF: convert it first, then open the JPEG anywhere. Converting to JPG loses AVIF's transparency and some of its size advantage, which is the price you pay for universal compatibility.

Is AVIF better than JPEG?

For file size, clearly: AVIF usually runs about 50 percent smaller at the same visible quality, and it adds transparency, animation, and higher color depth JPEG cannot match. The tradeoff is a slower encode and weaker app support, which is why JPEG still wins for anything you send to someone else's software rather than serve from your own site.

What opens an AVIF file?

Any current web browser opens a .avif file: drag it into a Chrome, Firefox, Safari, or Edge tab and it renders. Desktop viewers are hit or miss depending on version, so if an app rejects the file, convert it to JPG or PNG and every program will open the result without complaint or a missing plugin.

How do I change an AVIF file to a PDF?

Convert the AVIF to JPG or PNG first, then place that image into a PDF using your operating system's print to PDF option or a document editor. Image compressors, including this one, output image formats rather than PDF, so the AVIF becomes a JPG or PNG on the way, and that image is what goes into the PDF.

What does AVIF stand for?

AV1 Image File Format. AV1 is the video codec the format borrows its compression from, and the file is that codec's image data stored in a HEIF container. AVIF is not a brand new compression method invented from scratch; it is a smart reuse of a proven video codec for single still pictures.

Are AVIF files safe to use?

Yes. An AVIF file is an ordinary image file, no more risky than a JPEG or PNG, and it carries no scripts or active content. The only practical caution is compatibility, not security: an old program may not open it, but nothing about the format itself poses a risk to your computer or your data.

AVIF is the smallest of the four formats this tool works with, and the gap is real rather than marketing. When you want the actual byte count on your own picture instead of a rule of thumb, run a JPG or PNG through the AVIF compressor and compare the result before deciding whether the slower encode is worth it for your images.