JPG to PNG Converter
- The Exif data, the colour profile and anything else the original carried are not passed on: the picture is decoded to plain pixels and a new file is written from them.
Needs JavaScript. Runs only here.
This page turns a JPG into a PNG on your own machine. Every conversion on this page runs in your browser. The picture is read, drawn and written on your own machine, and the file is not sent to a server.
Going the other way? Convert PNG back to JPG →
How do you convert a JPG to a PNG?
A JPG carries a photograph that JPEG compression has already thinned out. Writing those same pixels as a PNG stores them with nothing further removed, and the file grows.
A JPG converted to PNG holds the same pixels the JPG already had, stored without further loss. Converting does not undo JPEG compression and does not add transparency: the picture stays opaque and the file usually grows.
- Choose the JPG file you want to convert. It is read inside this page, on your own machine.
- Select Convert to PNG. The page reads the first bytes of what came back and refuses the file if they are not PNG.
- Download the PNG. Nothing has been sent anywhere, so the file is ready as soon as it is written.
What Changes From JPG to PNG
JPG to PNG keeps every pixel the JPG already had and adds nothing. The JPEG compression that happened before you got the file is baked into those pixels, and the PNG has no transparency to give an opaque photograph.
Each row below is one property of the picture: what it is in the JPG, what it becomes in the PNG, and whether it survives the trip. Convert a file and the same rows fill in with the measurements from your own picture.
| Property | In the JPG | In the PNG | Verdict |
|---|---|---|---|
| Dimensions | as the file has them | as the file has them | kept |
| Colour model and bit depth | Y'CbCr, 8 bits per channel | RGB with alpha, 8 bits per channel — 8 bits per sample, whatever the source held | changed |
| Alpha channel | none — JPEG defines no alpha channel | none — PNG can carry one, this picture has nothing to put in it | not gained |
| Colours used | up to 16,777,216 | the same pixels | kept |
| Animation frames | 1 | 1 | kept |
| Metadata (Exif, ICC) | present in the file | dropped — a new file is written from pixels | lost |
| Compression | lossy, discrete cosine transform (the baseline process) | lossless, deflate | changed |
| File size | the file you chose | usually larger | changed |
the pixels survive; the Exif data does not.
Going Back to JPG
Converting back does not restore what this step dropped, so convert the PNG result back to JPG only when you need a JPG file.
The change above runs one way — go back from PNG to JPG writes a new file, not the original.
What Travels With the Picture
What the two formats are, and what the browser does with a picture on the way between them. None of this depends on which JPG you bring.
How JPG and PNG Are Defined
| Property | JPG | PNG |
|---|---|---|
| Compression | lossy, discrete cosine transform (the baseline sequential process); the standard also defines a separate lossless mode that web .jpg files do not use | lossless - deflate with a sliding window of at most 32768 bytes (compression method 0) |
| Alpha channel | none - neither T.81 nor JFIF defines an alpha or transparency channel | yes - a full alpha channel on colour types 4 and 6; a tRNS chunk gives a transparent colour key on types 0 and 2 and per-entry alpha on type 3 |
| Animation | none - one image per file | yes - APNG is normative in the Third Edition, using the acTL, fcTL and fdAT chunks |
| In one sentence | JPEG saves space by throwing detail away. The baseline process, which is what a .jpg file on the web uses, is lossy and cannot be undone, and the standard defines no transparency at all. | PNG stores a picture without losing anything: the specification defines lossless as reconstructing the original data exactly, bit for bit. It carries an alpha channel, and since the Third Edition it can carry frame-based animation as well. |
- A JPG file begins FF D8 (SOI); a JFIF file follows it with FF E0 and the identifier 4A 46 49 46 00.
- A PNG file begins 89 50 4E 47 0D 0A 1A 0A.
- JPEG is defined by ITU-T Rec. T.81 | ISO/IEC 10918-1 (JPEG); ITU-T Rec. T.871 | ISO/IEC 10918-5 (JFIF).
- PNG is defined by PNG Specification (Third Edition), W3C Recommendation 24 June 2025; the Second Edition is ISO/IEC 15948:2004. The Third Edition is not itself an International Standard..
JPEG and lossy WebP save space by discarding picture detail, and what they discard does not come back. PNG, BMP and lossless WebP keep every pixel they are given, and GIF keeps every pixel it is left with after the palette has been applied.
PNG, GIF, WebP and ICO can carry transparency; JPEG cannot, because the standard defines no alpha channel, and a bitmap written here is opaque. Converting to a format without transparency fills the clear areas with a background colour.
Every save as JPEG compresses the picture again. A JPEG that has been converted and saved once more carries the loss from both steps, and the second one cannot be undone by going back.
Converting a picture back to the format it came from does not return the original file. Whatever a step discarded stays discarded, and the return trip writes a third file.
The browser decodes the picture to plain pixels and writes a new file from them, so the Exif data, the colour profile and anything else the original carried are not passed on.
A canvas holds pixels and nothing else, so a file written from one carries no Exif data, no thumbnail and none of the original file's other metadata. The canvas specification never mentions Exif; this follows from writing the file out of a bitmap.
A browser has to be able to write PNG and may write other formats. If it is asked for a format it does not support it writes a PNG instead, without reporting an error, so a converter has to check what came back rather than trust what it asked for.
What Does a PNG Keep From the JPG?
What the PNG keeps
Every pixel the JPG handed over, exactly as it stood. PNG reconstructs the data it was given bit for bit, so the picture you see in the PNG is the picture the browser drew from the JPG, down to the last sample.
What it cannot give back
Detail the JPEG encoder removed before the file reached you. That happened once, on someone else's machine, and no later step can work out what used to be there. A soft edge or a blocky sky arrives in the PNG looking the same.
Why the file usually grows
PNG compresses without throwing anything away, and that costs space. A photograph has few exactly repeated runs for deflate to work with, so a PNG of a photograph is often several times the size of the JPG it came from.
Common Mistakes
- Expecting a transparent background. A JPG has no alpha channel to carry across, so the PNG opens with an alpha channel that is fully opaque everywhere.
- Treating the PNG as a repair. It is a faithful copy of a picture that has already lost detail.
- Sending the PNG where the JPG would do. For a photograph on a web page the JPG is usually the smaller file by a wide margin.
Frequently Asked Questions
Does converting a JPG to PNG restore the quality the JPG lost?
No. The detail went when the JPEG was written, and nothing later can work out what was there. The PNG copies what is left, faithfully.
Why is the PNG larger than the JPG it came from?
PNG keeps every pixel it is given, and a photograph gives deflate little to work with. The JPG is small because it threw detail away; the PNG is large because it does not.
Does converting a JPG to PNG make the background transparent?
No, and this is the most common expectation to correct. PNG, GIF, WebP and ICO can carry transparency; JPEG cannot, because the standard defines no alpha channel, and a bitmap written here is opaque. Converting to a format without transparency fills the clear areas with a background colour.
Does converting a JPG to PNG keep the photo's EXIF data?
No. The picture is decoded to plain pixels and a new file is written from them, so the camera data, the colour profile and the thumbnail are all left behind.
You can, but the round trip is not the file you started from: the PNG to JPG direction.
Related Conversions
The rest of the family sits on every image format this site converts.