Convert images to JPG
Turns a PNG, a WebP or an iPhone HEIC into a JPG, and goes the other way too — you can save as PNG or WebP instead. Set the long edge and the quality in the same pass. Nothing is uploaded; the conversion happens in this browser tab.
JPG converter
Checking which image formats this browser can save.
Why the form on the other end wants a JPG
Most of the time you are not converting because you want to — something downstream refuses the file you have. An application portal lists .jpg and .png and stops there. A print shop's uploader rejects anything else. A work laptop opens the WebP you saved from a web page with the wrong program, or with none at all, because WebP support arrived late on the desktop and older image viewers never got it. And a photo straight off an iPhone comes over as .heic, which plenty of forms have never heard of.
All four end the same way: the picture is fine, the container is wrong. This tool redraws the image and writes it out in the format you pick, so the file really is a JPG — not a PNG wearing a .jpg name. It reads JPG, PNG, WebP and HEIC, and it writes JPG, PNG and WebP. It cannot write HEIC, because browsers have no HEIC encoder; if you need to go back to HEIC, there is no route here.
What the three settings do
They are read straight off the tool above, and they are the whole interface — there is nothing hidden behind an advanced tab.
| Setting | Range | What it changes |
|---|---|---|
| Save as | JPG, PNG, WebP | The format written into the file. The list is built by actually encoding a test image, so a format your browser cannot write never appears. |
| Long edge | Original, or 6,000 down to 800px | Scales the photo so its longer side matches. Picking a number larger than the photo already is leaves it alone. |
| Quality | 50 to 95, starts at 85 | How much detail the encoder is allowed to throw away. The slider greys out when PNG is selected, because PNG does not throw anything away. |
If a size cap is what you are fighting, reach for the long edge before the quality slider — dropping the pixel count costs you less visible detail than pushing quality down into the fifties. The slider stops at 50 for that reason. Every finished file is named after the original with -converted added, and a ZIP of the batch comes out as blurmate-converted-images.zip.
Where people get caught out
Renaming the file to .jpg makes it a JPG
The extension is a label, not the contents. Rename a .png to .jpg and the bytes inside are still PNG. Viewers usually shrug and open it anyway, which is why the trick feels like it works — right up to the upload form that reads the first few bytes and says no. Converting rewrites those bytes.
Transparency survives the trip to JPG
JPG has no transparency, so it has to be filled in. This tool fills it with white. A logo on a transparent background comes out as a logo on a white rectangle. If the transparency matters, save as PNG or WebP instead — both keep it.
Saving at quality 95 improves a JPG
Re-encoding a JPG cannot bring back detail the first save discarded. You get a bigger file holding the same, or slightly worse, picture. Re-saving a JPG as a JPG is worth doing only when you want it smaller or narrower.
A bigger long edge means a bigger photo
It only ever shrinks. Choose 4,000px for a photo that is 1,200px wide and you get 1,200px back. There is no upscaling here, and no setting that adds detail that was never captured.
One side effect worth knowing: the converted file carries no metadata. No capture location, no camera or phone model, no timestamp. The image is redrawn onto a canvas in the browser and exported from there, and the original file's data does not come along. That is usually a relief for anything you are submitting, and a problem if you were relying on the location — keep the original for that.