Image format converter

Nothing is uploaded

The image is decoded and re-encoded by JavaScript in your own tab, and handed back as a download. There is no upload step because there is no code here that sends anything anywhere: load the page, turn off your network, and it converts exactly the same.

Browsers read far more formats than they write

This is the single most important thing about a browser-based converter, and most of them do not mention it.

Reading is broad: JPEG, PNG, WebP, GIF, BMP, ICO, SVG, AVIF on most browsers, HEIC on Apple devices. If your browser can display it, this can open it.

Writing goes through a canvas, and a canvas writes three formats: PNG, JPEG and WebP. That is the whole list, and it is why the output options here are short while the input accepts almost anything.

The failure this tool is built to avoid

Asked to write a format it does not support, a canvas does not raise an error. It quietly produces a PNG instead.

So a converter that offered AVIF output on a browser without an AVIF encoder would hand you a PNG named .avif, a file that opens nowhere and looks like a corrupted download. This asks your browser what it can actually write, disables anything it cannot, and checks the result’s own type before handing it over.

What every conversion costs

• To JPEG, transparency goes. JPEG cannot store a transparent pixel, so see-through areas are filled with white, right for a logo on a light page, wrong anywhere else.
• To a lossy format, detail goes. PNG to JPEG or WebP discards information permanently. Converting back does not bring it back.
• Animation goes. A canvas holds one picture, so an animated GIF or WebP arrives as its first frame.
• Metadata goes. EXIF, camera details, colour profiles and GPS coordinates are all dropped.

The tool works out which of these apply from the two formats and shows them before you convert, rather than as an apology afterwards.

JPEG to PNG does not repair anything

A common and understandable mistake. PNG is lossless, so converting a JPEG to one feels like an upgrade, but lossless means it preserves exactly what it is given, including every compression artefact the JPEG already has.

The result is a much larger file containing the same damage. Converting that way is worth doing when you need a format that holds transparency for further editing, and not otherwise.

SVG is a one-way trip

An SVG is a set of drawing instructions, so it stays perfectly sharp at any size. Converting it produces a fixed grid of pixels at one size, which blurs the moment anything enlarges it. There is no way back. The shapes are gone.

Which to choose

PNG for screenshots, logos, diagrams and anything containing text. JPEG for photographs going to someone whose software you do not know. WebP for photographs going onto a web page, where its 25–35% saving over JPEG is worth having and every current browser displays it.