Why convert PNG to JPG
PNG stores every pixel exactly as it was. That is wonderful for a logo and wasteful for a photograph, where nobody can see the difference and the file is several times larger than it needs to be.
The gap is not small. A photograph saved as a 1600-pixel PNG came to 2,248 KB in our own testing; the same image as a JPG at quality 85 was 344 KB — about a sixth the size, with no visible difference at normal viewing distance.
That is the whole reason to convert PNG to JPG: photographs do not need lossless storage, and everything that handles images handles JPG.
Where the saving actually matters
Email attachments, upload limits on forms, website page weight, and phone storage. All four are counted in bytes, and a photograph in PNG is spending five of every six of them on detail nobody will ever look at.
Why a PNG photograph is so large
PNG compresses by finding exact repetition — runs of identical pixels, rows that resemble the row above. A drawing is full of that. A photograph has almost none: adjacent pixels differ slightly everywhere, because real light and real sensors are noisy.
So PNG stores a photograph nearly pixel by pixel. JPEG instead throws away the differences your eye cannot resolve, which is why the same picture fits in a fraction of the space.
Is JPEG the same as JPG?
Yes. JPG and JPEG are the same format, with two spellings. There is no difference in the bytes, the compression, the quality or what can open them. A file named photo.jpg and one named photo.jpeg are read by exactly the same decoder.
Why two spellings exist
JPEG is the name of the format, defined in 1992 by the Joint Photographic Experts Group. Early Windows and MS-DOS allowed only three characters after the dot, so .jpeg was truncated to .jpg, and the habit outlived the limitation.
Which one should you use
Whichever the thing you are uploading to asks for. If it does not ask, use .jpg — it is the more common spelling and nothing rejects it. When you convert PNG to JPEG here, the file you get is a .jpg, and that is the same thing.
What happens to transparency
This is the part most converters do not mention, and it is the one thing in a PNG to JPG conversion that genuinely destroys something.
Why JPG cannot store transparency
A PNG can record how see-through each pixel is, in a fourth channel alongside red, green and blue. JPEG has only the three. There is nowhere to put transparency, so it has to become a colour.
Choosing the background colour
Every converter we tested fills transparency with white. One of them says so; the others do not mention it at all.
White is right often enough to be a sensible default, and wrong often enough to matter. A logo with a soft drop shadow gets a grey halo on white. Artwork drawn for a dark interface arrives in a bright box. This tool lets you pick white, black, or any colour you like.
What white does to a drop shadow
A shadow is not a shape with an edge — it is transparency fading from about 40% down to nothing. Composite that onto white and the fade runs to white, which looks correct on a white page and like a grey smudge anywhere else.
Composite it onto the colour the image will actually sit on and it disappears properly. That is a thirty-second decision the tool cannot make for you, because it does not know where the picture is going.
We tell you which files need the decision
Before anything is converted, each file’s header is read to see whether it can hold transparency at all, and the ones that can are flagged. No decoding, no waiting — and no discovering the problem after you have downloaded twenty files.
How to convert PNG to JPG
Add your files, choose a background colour if any of them are transparent, and convert. Everything happens on your own machine.
Quality, and why 85 is the default
JPEG’s quality dial trades detail for bytes, and the curve is steep at the top. On our test photograph, quality 95 produced 557 KB and quality 85 produced 344 KB — 38% smaller for a difference you have to hunt for.
Below 80 the losses start showing on skin tones and gradients. 85 is the point where the trade is still clearly worth making.
When to push it higher
Gradients, sunsets, skies and skin are where JPEG artefacts appear first. If the image is mostly smooth tone, 90 or 95 costs a couple of hundred kilobytes and removes the banding.
When you should not convert PNG to JPG
JPEG compresses in blocks of 8×8 pixels and smooths what is inside them. On a photograph you will never see it. On anything with hard edges it is obvious.
Screenshots and text
We measured a 1200×800 screenshot of text: 228 KB as PNG, and 239 KB as a JPEG at quality 95 — larger than the original, with visible ringing around every letter. Worse quality at a worse size. Screenshots should stay PNG.
Logos, icons and line art
Flat colour compresses extremely well in PNG and badly in JPEG. A logo also usually needs its transparent background, which JPG cannot keep. Both reasons point the same way.
Anything you will edit again
Every JPEG save throws away a little more. If the file is a working copy you will open and re-save, keep it lossless and export a JPG at the end.
When people actually need this
The reasons to convert PNG to JPG are boringly practical, and knowing which one you have tells you what settings to use.
An upload that keeps refusing the file
Job applications, government portals, university systems and ticketing sites often cap uploads at 1 MB or 2 MB and accept JPG only. A phone screenshot or a PNG export sails past that limit easily.
Convert at quality 80–85 and the file usually lands well under the cap. If it still does not, the image is too large in pixels rather than too rich in detail — reduce the dimensions rather than punishing the quality.
Photos going onto a website
Page weight is the single easiest performance win most sites have. Swapping PNG photographs for JPGs at quality 85 typically cuts image bytes by 80% or more, which is felt immediately on a phone connection.
If the site is modern, WebP or AVIF go further still — our HEIC to WebP and HEIC to AVIF pages cover those, and the same trade-offs apply.
If you are going the other way — you saved a .webp off a website and something will not open it — our WebP to JPG converter handles that, and warns you when the file turns out to be animated.
And if the destination is a website rather than a person, consider skipping JPG entirely: PNG to WebP is smaller again, keeps the transparency, and has a genuinely lossless setting.
Sending pictures to someone else
Mail servers reject large attachments, and messaging apps re-compress whatever you send them anyway. Converting first means you decide what the quality loss looks like instead of leaving it to somebody else’s server.
A folder full of exports
Design tools export PNG by default, which is right while you are working and wrong once the images are photographs headed for the web. Convert the folder in one pass and download it as a ZIP rather than doing it one file at a time.
PNG vs JPG at a glance
| PNG | JPG / JPEG | |
|---|---|---|
| Compression | Lossless | Lossy |
| Transparency | Yes | No |
| Best for | Logos, screenshots, line art | Photographs |
| Photograph file size | Large | About 1/6 the size |
| Text and edges | Crisp | Ringing artefacts |
| Re-saving | Safe | Degrades each time |
If you have the opposite problem, our HEIC to PNG converter handles iPhone photos, and you can also convert HEIC to JPG directly. Whichever format you end up with, it is worth checking what else is inside the file — you can remove EXIF data including GPS coordinates without re-encoding the picture.
What the conversion does not change
Two things people reasonably worry about, and neither happens here.
Your dimensions stay the same
Converting PNG to JPG changes how the pixels are stored, not how many there are. A 4000×3000 PNG comes back as a 4000×3000 JPG. If you also need it smaller on screen, that is a separate job — our HEIC resizer handles resizing.
Your original is untouched
The file on your disk is never modified. The converter reads it, builds a new JPG in memory, and hands you a download. If you dislike the result, change the quality or the background colour and convert again from the same source.
Privacy: why this runs in your browser
The conversion engine is WebAssembly running on your own device. Your PNG files are never uploaded, never queued on a server, and never held for an hour “for your convenience”.
For a holiday photo that may not matter much. For a screenshot of a document, or a photo taken at home with location recorded, it matters a great deal — and the same tool should not behave differently depending on which one you happen to drop in.
It also makes the batch behaviour honest. Converting forty PNG files to JPG costs us nothing, because your machine is doing the work, so there is no quota to invent and no premium tier to sell you.
The trade is that the first conversion waits a moment for the engine to load. After that everything is local, and it keeps working if your connection drops.