What this browser can open and write
Not a chart copied from somewhere else. The table below is filled in by this page, now, by asking your browser to open a tiny sample of each format and to write each one back.
Tested just now
| Format | Opens | Writes |
|---|---|---|
| JPEG | checking | checking |
| PNG | checking | checking |
| WebP | checking | checking |
| GIF | checking | — |
| AVIF | checking | checking |
| BMP | checking | — |
| ICO | checking | — |
| TIFF | checking | — |
| HEIC | checking | — |
Each “yes” is a two-pixel sample this tab just decoded, or a canvas it just asked for JPEG, PNG, WebP, AVIF and checked what came back. HEIC has no sample, so it is tried on the first real one you open.
What a conversion keeps
| Output | Keeps | Worth knowing |
|---|---|---|
| JPEG | Colour, not transparency | Lossy. Every re-save is another pass. |
| PNG | Colour and transparency | Lossless. Right for drawn pictures, heavy for photographs. |
| WebP | Colour and transparency | Lossy here, with alpha. Opens in every current browser. |
| AVIF | Colour and transparency | Written only where the browser’s own encoder can. |
Whatever the output, some things never survive a conversion done in a browser, and the converter says so rather than implying otherwise. Camera metadata, GPS positions and XMP are not written: a browser’s encoder writes pixels. The source’s colour profile is not carried over either — at most the new file is tagged sRGB. Everything is decoded to 8-bit sRGB first, so a 16-bit PNG or a Display P3 photo arrives as 8-bit sRGB. EXIF orientation is applied to the pixels, so a phone picture stays upright without a flag to rely on.
An animated GIF, WebP or PNG becomes its first frame, or is left out of the batch entirely if you tell the converter to skip animations. Transparency survives into PNG and WebP; JPEG has nowhere to put it, so a transparent file waits for you to choose the colour it is flattened onto before any JPEG of it is written.
When a file will not open
It stays in the list, set apart from the rest, with its name, the format its bytes turned out to be, and the reason — never silently dropped and never sent somewhere else to be decoded. HEIC is the common case: Safari has a decoder of its own, most other browsers do not. TIFF is the other one. Saving the file again as JPEG or PNG from wherever it came from always works.
Open the converter to try your own files against the same table.