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Need help?AVIF to AVIF — Almost Always Bigger Than You Expect
AVIF is the AV1 Image File Format: AV1-coded pixels inside an ISO base media container derived from HEIF. The Alliance for Open Media maintains the specification and shipped version 1.2.0 on December 9, 2025. Because AVIF is normally used as the compressed delivery format, most AVIF files you encounter were already squeezed hard — which makes a same-format pass behave in a way people rarely predict.
The default quality preset on this page is higher than the setting almost anything used to write your source. Re-encoding at it does not shrink the file; it multiplies it, sometimes several times over, while still costing a generation of quality because our servers always decode and re-encode. The measurements below are the most useful thing on this page, so they come first.
Legitimate reasons to run this conversion: hitting a hard size limit, cutting the pixel dimensions down, or forcing a batch of mismatched exports onto one setting. Free, no sign-up, no watermark; files upload over an encrypted connection and are deleted automatically after a few hours.
What the Quality Preset Does to an Already-AVIF File
Measured on a detailed 1600x1200 photographic image encoded to AVIF at three typical source qualities, then re-encoded through this page's presets. Highest is quality 100, Very High (the default) is 95, High is 90, Medium is 80.
| Source AVIF | Highest | Very High (default) | High | Medium |
|---|---|---|---|---|
| 19 KB (aggressive web export) | 1.02 MB | 150 KB | 90 KB | 30 KB |
| 62 KB (typical web export) | 1.35 MB | 349 KB | 192 KB | 79 KB |
| 264 KB (high-quality export) | 1.91 MB | 705 KB | 490 KB | 320 KB |
Two conclusions. First, never choose Highest on an AVIF source — quality 100 asks the encoder to reproduce the previous encode's noise floor exactly, which is enormously expensive and gains you nothing visible. Second, if the goal is a smaller file, you need Medium or below, or Specific file size, which lets you name the kilobyte or megabyte figure and works out the rest. If shrinking is the only goal, Compress AVIF opens on a "Target file size (%)" slider that this converter deliberately hides.
How to Re-encode an AVIF Image
- Upload Your AVIF Files: Drag and drop, or click "+ Add Files". Batch uploads share one set of settings, which is exactly what you want when normalising a folder of exports.
- Choose a Quality Preset or a Size Target: Image Compression opens on Quality Preset at "Very High (Recommended)", which is quality 95. Given the table above, Medium or Low is usually the sensible choice on an AVIF source. Switch to Specific file size when a form or a page-weight budget gives you an actual number; it accepts bytes, kilobytes or megabytes and has an Auto Scale toggle that lets dimensions drop if quality reduction alone cannot reach the target.
- Set the Dimensions: Image resolution starts on Keep original. Resolution Percentage scales by a share of the source; the Preset list is height-based and runs from 4320p down to 144p plus a set of small icon steps that includes 256P, 192P, 180P, 128P, 64P, 48P, 32P, 24P and 16P; Width and Height each lock the aspect ratio; Width x Height sets both exactly. Reducing pixels is by far the most effective way to shrink an AVIF that is already well compressed.
- Convert and Download: Click Convert and take the files individually or as a ZIP. Uploads and outputs are deleted automatically after a few hours.
What Survives, and What This Page Does Not Offer
| Element | Behaviour |
|---|---|
| Transparency (alpha channel) | Preserved. A four-channel AVIF comes back four-channel |
| EXIF metadata | Preserved — camera make, model and the rest carry through |
| Pixel dimensions | Preserved unless you change them under Image resolution |
| An animated or multi-image AVIF | Written back as a single still image. The image-to-image path writes one frame, so an animation is flattened |
| Lossless mode | Not offered on this page. Every output is a lossy AV1 encode |
| Bit-depth control | Not offered. There is no 10-bit or 12-bit selector here |
| Encoder effort / speed control | Not offered |
| Chroma subsampling control | Not offered; the encoder decides |
If you need an animation preserved, convert to a format built for it rather than back to a still: a video or animated-image target keeps the frames. If you need lossless, AVIF is not the route on this site — a PNG at the Highest preset is the lossless path.
Frequently Asked Questions
Why did my AVIF get bigger after converting it to AVIF?
Because the default preset is quality 95 and your source was almost certainly written far below that. Web tooling commonly exports AVIF somewhere in the 45-65 range, where the format's efficiency really shows. Asking a fresh encode to preserve that already-lossy image at 95 costs several times the bytes. Drop to Medium, Low or Very Low, or use Specific file size and name the figure you actually need.
Does AVIF to AVIF lose quality?
Yes. Our servers decode the image and encode it again — there is no copy-through path — and AVIF at anything short of a lossless mode is a lossy codec. Because the source is itself AVIF, the second encode wastes effort faithfully reproducing the first encode's artefacts. Whenever you still have the original photograph or PNG, re-export from that instead of round-tripping the AVIF.
Will transparency survive?
Yes. AVIF carries a full alpha channel and it is preserved through the conversion — a four-channel image in gives a four-channel image out. Nothing is flattened onto a background colour on this page.
What about EXIF and GPS data?
Metadata carries through. Camera make and model, exposure information and location data all survive a same-format pass, which is convenient for a photo workflow and a privacy consideration if the image is about to be published. Strip it with a dedicated tool beforehand if that matters.
My AVIF is animated. Why did I get a still image back?
Because an image-to-image conversion writes one image. AVIF can store an image sequence, but this page's path reads a single frame and encodes a single frame, so the animation is lost without an error. Convert to a video or an animated-image format instead if the motion is the point.
How widely is AVIF supported now?
Very widely in browsers — caniuse currently puts global support at about 94.7%, with Chrome from version 85, Firefox from 93, Safari from 16.4 and Edge from 121. Outside the browser it is patchier: some desktop image viewers, older photo managers and a fair number of upload forms still refuse it. AVIF to JPG is the escape hatch when something will not take the file.
Can I set a 10-bit or lossless AVIF here?
No. This page exposes a quality preset, a file-size target and resolution controls — there is no bit-depth selector, no lossless toggle and no encoder-effort control. Those are AVIF capabilities that the format supports and this converter does not surface, so use a dedicated local encoder if you need them.
How small can an AVIF realistically get?
Below a certain point, quality reduction alone stops helping and you have to remove pixels. That is why Auto Scale exists on the Specific file size control, and why the Image resolution section matters more here than on most formats. A 4000-pixel-wide photo taken down to 1600 pixels shrinks dramatically and still looks sharp on any screen it will realistically be viewed on.
Is AVIF royalty-free?
Yes — that is the central design goal of the Alliance for Open Media and the practical difference between AVIF and HEIC, which uses the patent-encumbered HEVC codec. It is why AVIF got browser support quickly and why HEIC never did. For converting your own files it changes nothing; for anyone shipping software it changes a great deal.
How long do you keep my images?
Uploads and their outputs are deleted automatically after a few hours. They are never shared, published or indexed, and no account, email address or payment is required.