PNG to JPG Converter

PNG is the right format for line art and the wrong format for photographs. If you have ever tried to attach a phone screenshot or a camera export to a form with a 2 MB limit, you have hit that mismatch: PNG stores a photograph as millions of individually-described pixels, while JPG stores it as a set of frequency coefficients tuned to what human eyes actually notice. Converting PNG to JPG is the fastest way across that gap, and this free PNG to JPG converter does it locally, in your browser, with no upload and no account.

How the PNG to JPG conversion works

The browser decodes your PNG into raw pixels, composites any transparent areas onto the colour you choose, and hands the result to its own JPEG encoder at the quality level you set. Every step of the PNG to JPG conversion runs in this tab: there is no upload, no queue and no watermark, because there is no server involved at all.

Each result is named after its source with a .jpg extension, and the row beneath it reads PNG → JPG · 1600 × 900 · 2.4 MB → 310 KB, so the saving is visible per file rather than only in the batch total. Up to 20 files of 25 MB each per run, converted one at a time; anything that fails to decode is reported by name while the rest carry on.

Choosing a quality level

The quality slider controls how aggressively the encoder quantises those coefficients, and it is the main lever on how small your PNG to JPG output gets.

• 95–100% — near-transparent. Use for archival copies and images that will be re-edited.
• 80–90% — the practical default. Photos look identical at normal viewing distance and files shrink by 60–80%.
• 60–75% — visibly softer on gradients and fine texture, but fine for thumbnails and previews.
• Below 60% — blocking and banding appear. Only worth it under a hard size cap.

Because the encoder belongs to the browser, the exact byte count for a given percentage differs between Chrome, Firefox and Safari. Treat the number as a consistent setting inside one browser rather than a portable guarantee, and read the result row for the size you actually got.

Handling transparent backgrounds

Because JPG cannot represent "no pixel", the PNG to JPG converter composites your image over a solid colour before encoding, and the three choices are white, black and light grey. White is the default and the safe answer for documents, product photography and anything heading for print. Black suits a screenshot or a logo that will sit on a dark page; light grey is the compromise when neither extreme is right.

Semi-transparent pixels are blended with the fill at their own opacity rather than replaced by it, so a soft drop shadow stays a soft drop shadow instead of turning into a hard outline. Where the destination has a background of its own and none of the three matches it, the more reliable route is not a PNG to JPG conversion at all: convert to WebP instead, because WebP keeps the alpha channel, so the page shows through and no colour has to be guessed at all.

If the image genuinely needs transparency, the correct move is not JPG. Use the WebP converter instead: WebP supports both a real alpha channel and lossy compression, so you get small files without losing the cut-out.

Keeping your originals

Treat the PNG to JPG export as a one-way delivery. Keep the PNG master, and generate JPG copies for sending. Re-opening a JPG, editing it and saving again compounds the loss with every cycle, which is how images end up with that unmistakable smeared look. The source PNG never leaves your machine and is never modified — only the exported copies are.

What the quality number is really doing

The percentage is handed to the browser's JPEG encoder as its quality argument, and the encoder uses it to decide how coarsely to quantise each 8×8 block of frequency coefficients. The relationship between the number and the byte count is not linear: the step from 100% down to 90% typically removes a third of the file, while 60% down to 50% removes far less and costs visibly more. That is why the useful range for a PNG to JPG conversion in practice is 80–95%, and why the slider stops at 40% rather than continuing lower — below that the output is mostly blocking artefacts with an image attached.

What else the conversion changes

The PNG to JPG output is written from a canvas, which carries pixels and nothing else, so three things go with it. Any EXIF block is dropped, including the orientation flag — which is why a photograph that displayed sideways in one application can come out upright here. Embedded colour profiles collapse to sRGB. And transparent pixels are composited onto the fill colour at full opacity.

The maximum dimension field is the other lever, and usually the stronger one. It caps the longest edge between 1 and 10000 pixels, preserves the aspect ratio, and never enlarges — an image already below the cap passes through untouched. Halving each dimension removes three quarters of the pixels, which no quality setting can match, so a PNG to JPG conversion paired with a sensible size cap is usually enough to clear any upload limit on its own.

When PNG to JPG is the wrong move

Flat-colour graphics such as logos, charts and screenshots sometimes come out larger as JPG than they were as PNG, because PNG compresses large uniform areas extremely well while JPG spends bytes on ringing artefacts around the edges. For that kind of image, keep the PNG or convert to WebP lossless instead. And if the image needs transparency at its destination, JPG is simply the wrong container — a PNG to JPG conversion always flattens transparency onto a solid colour, by the nature of the format.

Batch PNG to JPG conversion, privately

Batch PNG to JPG conversion runs entirely on your device, so a folder of screenshots or client photographs can be converted without a single byte leaving it. Add up to 20 files, pick one quality and one background colour, press Convert to JPG, and every file is processed with the same settings and listed with its own download button and size comparison. No account, no daily cap and no upload — the same privacy every tool on CollabsTool is built around.