🔄 Image Converter

Convert between PNG, WebP, AVIF and JPEG — with an honest size verdict. Runs entirely in your browser; nothing is uploaded.

About the Image Converter

Different image formats exist because they make different trade-offs, and the right one depends on where the image is going. This tool converts between the four formats the web actually uses — PNG, JPEG, WebP and AVIF — inside your browser, showing the size consequence of each choice before you download anything.

A rule of thumb worth having: photos belong in WebP or AVIF (JPEG when compatibility with old software matters), screenshots and graphics with text or sharp edges belong in PNG or lossless WebP, and transparency rules out JPEG entirely. When a conversion makes the file bigger — which genuinely happens — the tool says so instead of letting you ship a worse file with a trendier extension.

How to use it

Drop an image — the tool identifies its real format from the file bytes, not the extension.
Pick the target format. A sensible default is pre-selected based on what you loaded.
Set quality for lossy targets; PNG is always lossless.
Check the size verdict, then download — the filename keeps your name with the new extension.

Frequently Asked Questions

Is anything uploaded when I convert an image here?

No. The conversion runs on the Canvas API inside your own browser — decode, re-encode, preview and download all happen locally. Your browser's network panel will confirm no request carries the image anywhere.

PNG to WebP made my file bigger. Why?

Small graphics, icons and images with few colours often compress better in PNG than in a lossy codec's container. WebP's big wins are on photographic content. The tool shows the size verdict honestly — when the conversion loses, keep the original.

What happens to transparency when I convert to JPEG?

JPEG has no alpha channel, so transparent areas must become a solid colour. This tool flattens onto white, which matches how browsers display JPEGs. If you need transparency, choose PNG, WebP or AVIF as the target instead.

Why is AVIF greyed out?

Your browser cannot encode AVIF. Decoding AVIF is widely supported, but encoding is newer — Chrome and Edge can, and where they can't, the tool loads a WebAssembly encoder as a fallback. If both are unavailable, the option is disabled rather than silently producing a PNG with the wrong extension.

Does converting preserve EXIF metadata and colour profiles?

No — going through a canvas strips EXIF, GPS data and ICC profiles. For publishing that is usually desirable. If the colour profile matters (wide-gamut photography workflows), a browser canvas is the wrong tool: use a desktop converter that manages colour.

Can I convert an animated GIF or animated WebP?

Only the first frame. Canvas decoding is single-frame, so animation is dropped and the tool says so when it detects a GIF. For animation, a video format via a desktop tool (ffmpeg) is the right conversion.

How to convert images between PNG, WebP, AVIF and JPEG

Image formats are trade-offs frozen into file structure: JPEG spends quality for small photographic files, PNG spends bytes for pixel-perfect fidelity and transparency, WebP and AVIF renegotiate both trades with two more decades of codec research. Converting between them is one of the most common small tasks in web development — and one that routinely gets done through sketchy upload sites that keep a copy of everything they touch.

Braxik's converter does the conversion in your browser. The file is identified by its real bytes (not its extension), decoded with the Canvas API, re-encoded in the target format, and offered back with a byte-accurate size comparison — all without the image crossing the network.

The tool pre-selects a sensible target based on what you load: photos arriving as JPEG or PNG default to WebP, because that is the conversion people usually want; WebP and AVIF files default to PNG, because the usual reason to convert those is an old tool that cannot open them. One click changes the target.

Conversion is also where honesty matters most. PNG-to-WebP famously shrinks photos and famously GROWS small graphics; the tool reports the real delta and says plainly when the conversion did not help, so you never ship a bigger file with a more modern extension.

How it works

The file's format is detected from its magic bytes — a ZIP renamed to .png is caught immediately with a message saying what the file actually is. The decoded image is checked against byte and pixel caps so oversized or malicious files fail with an explanation rather than a dead tab.

Encoding runs in a Web Worker on an OffscreenCanvas. When converting transparent images to JPEG — a format with no alpha channel — the image is flattened onto a white background first, matching how browsers display JPEGs, so transparency loss is visible and predictable rather than turning black.

AVIF encoding is feature-detected before the option is offered. Where the browser cannot encode AVIF natively, a WebAssembly encoder is loaded on demand as a fallback; if neither is available the option is disabled — never silently substituted with a mislabelled PNG.

Common uses

Convert WebP or AVIF images (increasingly what you get when you save from the web) back to PNG or JPEG for tools that cannot open them.
Convert PNG screenshots to WebP before publishing documentation, cutting page weight roughly in half at no visible cost.
Produce a JPEG from a transparent PNG for systems that reject transparency or alpha channels — ID photo uploads, legacy CMS fields.
Convert a JPEG to PNG before pixel-precise editing, so subsequent saves don't compound JPEG's generational loss.
Standardise a mixed folder of image formats into one format for a build pipeline or asset catalogue, one honest conversion at a time.
Create AVIF versions of key images for browsers that support it, keeping WebP/JPEG fallbacks via the <picture> element.
Turn an AI-generated PNG into a web-ready WebP without routing possibly-sensitive content through a third-party upload service.

Before you rely on the result

Check the size verdict before downloading — if the conversion made the file bigger, the original format was the right one for that content.
Converting to JPEG flattens transparency onto white; if you need the transparency, pick WebP, AVIF or PNG as the target instead.
Remember conversion cannot restore quality a lossy format already discarded — JPEG-to-PNG produces a faithful copy of the compressed image, not the original scene.
For photos going to the web, pair conversion with the quality slider: WebP at 80% is usually the sweet spot of the size/fidelity trade.
Animated GIFs and animated WebP convert as their first frame only; use a video format for animation.
Wide-gamut and colour-managed images lose their ICC profile in a canvas re-encode; use a desktop converter when colour accuracy is contractual.
Verify unusual files after conversion by reopening the output — a file that decodes wrongly (truncated, corrupted) fails loudly here, but the check costs one double-click.