Free converters · Run in your browser
Free image converters
Short answer
20 image converters, free and with no upload, including HEIC from an iPhone and AVIF. What a conversion does to the size depends on the direction and the picture: a 29.82 MB PNG photograph became a 3.60 MB JPG, a 94.6 KB text screenshot grew to 129 KB, JPG to PNG made a 3.10 MB photo 29.97 MB, and an AVIF of 82.0 KB became a JPG of 198 KB.
The converters we measured
Camera RAW files (the JPEG preview inside)
Pictures to PDF
Every image converter
20 pairs. Each page has a working converter, the facts about both formats and, where we measured it, what the conversion does to the size.
Key takeaways
- Photographs shrink going to JPG (29.82 MB to 3.60 MB), but flat graphics and text screenshots can grow (94.6 KB to 129 KB).
- Going to a lossless format only adds size: JPG to PNG took 3.10 MB to 29.97 MB with no gain in detail, and WebP to JPG took 2.33 MB to 3.71 MB.
- Newer formats are much smaller: our AVIF was 82.0 KB and the same picture as a JPG was 198 KB.
- HEIC works in every browser here: a 15 megapixel HEIC decoded in 1.4 s and became a 3.58 MB JPG at the default quality.
- The converters read 8 of the 9 input formats we tried in Chromium; TIFF was not read.
Measured: what each conversion does
Image conversions run through the converter's own steps in headless Chromium: the picture is drawn on a canvas and saved at quality 0.92, with a white background for JPEG. HEIC is decoded by libheif compiled to WebAssembly. The test files are public domain NASA scans, one with transparency, a screenshot of a page of this site, and AVIF and HEIC files we made from the scans.
| Conversion | Test file | Before | After | Change | SSIM |
|---|---|---|---|---|---|
| PNG to JPG | Photo | 29.82 MB | 3.60 MB | -87.9% | 0.991 |
| PNG to JPG | Text screenshot | 94.6 KB | 129 KB | +36.7% | 0.992 |
| JPG to PNG | Photo | 3.10 MB | 29.97 MB | +866% | 1.000 |
| WebP to JPG | Photo | 2.33 MB | 3.71 MB | +59.3% | 0.981 |
| AVIF to JPG | Portrait | 82.0 KB | 198 KB | +141.8% | 0.978 |
| HEIC to JPG | Photo, HEIC quality 75 | 4.35 MB | 3.58 MB | -17.7% | 0.989 |
Size before and after, and SSIM against what the browser read from the input.
The rows show why "convert" does not mean "smaller": the direction and the content decide.
Formats at a glance
| Format | Compression | Transparency | Best for |
|---|---|---|---|
| JPG | Lossy | No transparency | Photos; the image format every platform documents |
| PNG | Lossless | Transparency supported | Screenshots, logos and graphics with text |
| WebP | Lossy or lossless | Transparency supported | Smaller images on websites; social platforms mostly document JPEG and PNG instead |
| AVIF | Lossy or lossless | Transparency supported | Small photographs on websites; MDN lists it as supported by Chrome, Edge, Firefox, Opera and Safari |
| HEIC | Lossy | Transparency supported | iPhone and iPad photos: Apple says it compresses better than JPEG at the same visual quality |
| SVG | Vector (no pixels) | Transparency supported | Logos and icons that must stay sharp at any size |
Limits to know about
- Images are saved by the browser's own encoder, so sizes can differ a little between browsers.
- The converted file carries only the picture: the date, location and camera details are not copied.
- JPG has no transparency; transparent areas become white. Use PNG or WebP to keep them.
- Only the first frame of an animated file is converted.
Questions people ask
Can I convert HEIC from my iPhone?
Yes. HEIC to JPG, PNG and WebP are supported, several files at once, and nothing is uploaded.
Does converting reduce quality?
Converting to a lossy format (JPG, WebP) is a lossy step; converting to PNG adds no loss but cannot restore detail that is already gone.
Why did my file get bigger?
Lossless targets are bigger by design (JPG to PNG was 9.7 times bigger), and modern formats like AVIF and WebP compress better than JPG, so converting from them grows the file.
Which format should I use for a screenshot?
PNG. Our text screenshot was 94.6 KB as PNG and 129 KB as JPG.
Is my image uploaded?
No. Every conversion runs in your browser.
Which formats can I convert?
JPG, PNG, WebP, AVIF, GIF, BMP, ICO and HEIC in our Chromium test; TIFF depends on the browser.
Sources and how we checked
- MDN: Image file type and format guide (read 2026-10-09)
- libheif (strukturag) README: HEIF and AVIF decoder and encoder (read 2026-10-09)
Reviewed October 9, 2026. Every figure on this page comes from the measurements behind the linked tool pages, which are saved in data/seo/hub/evidence/2026-10-09.