There is no conversion API, and there will not be one

Worth saying up front, because it is the first thing a developer looks for. A REST endpoint that converts an image means the image travels to a server, and not doing that is the entire point of ImageConvert.tools. There is no hosted conversion API here and adding one would make the site's central claim false.

What can be published without breaking anything is the knowledge. Working out which format supports an alpha channel, which can animate, which survives an EXIF round trip and which conversions are even possible turns out to be a research task every time, and the answer does not exist anywhere in a form a program can read. So here it is.

The endpoint

GET https://imageconvert.tools/api/formats.json

Served as application/json with Access-Control-Allow-Origin: *, so it works from a browser as well as from a script. Version 1.0.0, last changed 2026-08-05.

const res = await fetch("https://imageconvert.tools/api/formats.json");
const data = await res.json();

// Which formats can carry an alpha channel?
data.formats.filter(f => f.supports.transparency).map(f => f.label);

// Can this converter turn a HEIC into a PDF?
data.formats.find(f => f.id === "heic").converter.convertsTo.includes("pdf");

What is in it

Per format:

mimeType and extensions
specification, the name and URL of the document that defines the format
introduced, the year it was first published or standardised
compression: lossless, lossy, lossy or lossless, uncompressed, or container
supports: transparency, animation, colour profiles, EXIF, vector
converter: whether this site can read it, write it, and the full list of targets it converts to with the page URL for each
notes, one paragraph of the context a boolean cannot hold

Plus a pipeline block naming the decoder and encoder used for every format, and a caveats array. Those caveats are in the file rather than only on this page on purpose: a dataset that travels without its caveats gets quoted without them.

The distinction that matters

supports describes the format. converter describes this implementation. They are not the same question, and conflating them is the most common error in format comparison tables. PNG can carry EXIF; this converter does not write any. GIF can animate; this converter writes a single frame. Read how it works for the full account of what the pipeline keeps and what it drops.

What is deliberately not in it

No file sizes, no compression ratios, no "X percent smaller" numbers. Publishing those would require a documented test set, a stated encoder version and a repeatable method, and until that exists any figure here would be decoration. The one percentage in the dataset is Google's own published WebP comparison, and it is labelled as Google's in the notes field rather than presented as a measurement of ours.

Licence

Creative Commons Attribution 4.0. Use it commercially, modify it, redistribute it. The one condition is attribution:

Image format capability dataset, ImageConvert.tools, https://imageconvert.tools/api

Corrections

Every entry was written from the specification named in it. If you find something wrong, tell us and it gets fixed, with the version number bumped. A dataset nobody can correct is not worth citing.

Coverage

11 formats can be read: PNG, JPG, JFIF, WebP, AVIF, GIF, BMP, TIFF, ICO, SVG, HEIC. 9 can be written: PNG, JPG, WebP, AVIF, GIF, BMP, TIFF, ICO, PDF. The three that are read but not written, and the reasons why, are set out on the conversion hub.