CleanorTools
AVIF

AVIF Alpha Checker

Details

How to use AVIF Alpha Checker

What the tool does, how to run it, and what to expect from the result.

How to check AVIF transparency

To inspect an image, upload one AVIF to the AVIF Alpha Checker and switch between the RGB, alpha, and alpha-mask views. The alpha and mask views reveal exactly which areas are transparent, translucent, or opaque, which the normal RGB preview alone cannot show.

After analysis, the tool reports the percentage of transparent, translucent, and opaque pixels, giving you a definitive answer on whether the AVIF carries real transparency. If you need a visual record, export the current alpha view as a PNG.

  • Upload one AVIF file
  • Switch between RGB, alpha, and alpha-mask views
  • Read pixel-type stats and export a PNG if needed

Why alpha inspection matters

An AVIF can technically support an alpha channel and still have messy edges or no meaningful transparency at all. The AVIF Alpha Checker makes that easy to verify before the asset moves downstream into a design, sticker, or web workflow that depends on clean transparency.

Because the analysis runs entirely in your browser, the AVIF is never uploaded to a server. You get a private, on-device check that is safe to run on client assets and unreleased graphics.

Tips

Getting a better result out of AVIF Alpha Checker

Specific settings and thresholds, not general advice.

  • The analysis is a pixel census, not a header read. Every pixel is bucketed by its alpha byte: exactly 255 counts as opaque, exactly 0 counts as fully transparent, and everything in between (1 to 254) counts as translucent, which is where anti-aliased edges and soft shadows live.
  • The percentages are rounded to whole numbers, so an image whose only transparency is a one-pixel anti-aliased outline on a large canvas will honestly report 0% transparent. Trust the alpha view over the number in that case.
  • The alpha mask view is a hard threshold at alpha 16 out of 255, roughly 6% opacity. Anything fainter than that shows as black in the mask, which tells you what a naive cut-out (a renderer with no alpha blending) would actually discard.
  • An AVIF with an alpha channel that turns out to be 100% opaque is wasting bytes. The alpha plane is encoded and stored whether or not it does anything, so if this tool reports no meaningful transparency, re-exporting without alpha will make the file smaller.
  • This is a read-only inspection. The source AVIF is never rewritten, and the PNG you download is a render of the view you are looking at, not a modified version of your image.
Limits

What AVIF Alpha Checker does not do

The honest boundary, so you do not lose time finding it yourself.

  • Still AVIF only. Animated AVIF sequences are not handled as animations.
  • The browser has to support the WebCodecs ImageDecoder API and OffscreenCanvas. Chromium-based browsers and recent Safari builds qualify; older browsers show an unsupported message and the tool is disabled.
  • It does not tell you why the alpha is there, whether it is premultiplied, or what matte colour was used behind it.
  • It does not modify, optimise, or strip the alpha channel. Use an AVIF optimiser or converter for that.
Reference

Terms used on this page

Short, plain-language definitions for the formats and settings above.

Files & formatsAVIFAVIF (.avif) is a next-generation image format based on the AV1 video codec. It typically produces smaller files than JPEG or WebP at the same quality and supports transparency, HDR, and wide color — making it one of the most space-efficient formats available.General
At a glance

Who AVIF Alpha Checker is for

A quick way to understand who this helps, what it solves, and where it connects next.

Best fit

Designers, QA, and frontend teams validating transparent AVIF assets before shipping or handing them off.

Ideal for

Checking whether an AVIF really contains usable alpha instead of assuming the format alone guarantees it.

FAQ

Common questions

Short answers for the questions people usually have before trying a utility like this.

Does this rewrite the AVIF?

No. The AVIF Alpha Checker is an inspection-first tool. It does not modify the source AVIF; the only export is a PNG of the current alpha preview.

Can I confirm whether the AVIF is actually transparent?

Yes. After analysis the tool reports transparent, translucent, and opaque pixel percentages, giving a definitive answer on whether the AVIF has meaningful alpha.

Does my AVIF get uploaded?

No. The AVIF Alpha Checker runs entirely in your browser, so the file stays on your device and is never sent to a server.

Is the AVIF alpha checker free?

Yes. It is free to use with no signup, and all inspection and PNG export happen locally in your browser.

What is the difference between the alpha view and the alpha mask view?

The alpha view renders the raw alpha channel as greyscale, where white is fully opaque and black is fully transparent, and everything between shows the soft gradients. The alpha mask is a binary version of the same thing, thresholded at alpha 16, showing only what would survive a hard cut-out.

It says 0% transparent but the image clearly has a transparent background. Why?

Almost certainly rounding. The percentages are whole numbers, so anything under half a percent of the pixels reads as 0. Switch to the alpha view, where any transparency will be visible as dark regions regardless of how few pixels it covers.

What counts as translucent?

Any pixel whose alpha byte is between 1 and 254. That includes anti-aliased edges, soft shadows, glass and glow effects, and any deliberately semi-transparent overlay. A high translucent percentage means the image genuinely needs full alpha rather than a one-bit cut-out.

Can I use this to remove the transparency?

No. It only inspects and renders. The PNG download gives you the alpha channel as an image, which is useful as a mask in an editor, but it does not produce a modified AVIF.

Why does the preview sit on a white background?

The alpha views are rendered as opaque greyscale images and displayed on white so that the black transparent areas read clearly. It is a display choice, not a change to your file.

Why can I not run it in my browser?

The decode uses the WebCodecs ImageDecoder API together with OffscreenCanvas, and not every browser ships both. If the page shows the unsupported message, a current Chromium-based browser is the reliable option.

Recommendations

You Might Also Like

Nearby tools from the catalog that fit the same job or workflow.

RGBA
UtilityChannels

PNG Channel Viewer

Inspect PNG channels

Inspect RGB and alpha channels from one PNG and export the current channel view as a new PNG.

WALP
UtilityAlpha

WebP Alpha Viewer

Inspect WebP alpha

Inspect WebP transparency, switch between RGB and alpha views, and export the current alpha render as PNG.

ALPHA
ImageTransparency

Image Transparency Checker

Check alpha and transparency

Check whether an image has transparency, review alpha stats, and preview the alpha mask locally.

TEST
UtilityPreview

PNG Background Tester

Test PNG on backgrounds

Preview a transparent PNG on white, black, checker, custom, and gradient backgrounds before export.

MAP
UtilitySEO

Sitemap Inspector

Inspect sitemap XML

Inspect pasted sitemap XML locally and flag missing or duplicate loc entries.

A2P
ImageAVIF

AVIF to PNG

Convert AVIF to PNG

Convert one AVIF into PNG locally and keep transparency when the source contains alpha.

Cleanor app

Do it all on your device

Cleanor puts these tools in one app: compress and convert images, video, and audio, work with PDFs, and scan text right on your device. Plus free up storage and clear inbox clutter with Email Cleaner. Start with a free trial.

  • iPhone
  • Android
  • Macsoon
  • Windowssoon
Get it on the App StoreGet it on Google PlayAll platforms & pricing