JPG to PNG converter
Freeze a JPG photo as a lossless PNG, so the next edits stop costing quality.
- Processed on your device. Your photos are never uploaded. How we know
- Free, no sign-up, no watermark
Drop JPG images to convert to PNG
Drop files, paste with Ctrl+V, or choose them from your device.
PixWrench’s code runs on your device. We don’t receive your files, file names or their contents.
PixWrench’s code runs on your device. We don’t receive your files, file names or their contents. What happens to your files
How to convert JPG to PNG
A JPG is built for sharing: small, good-looking and lossy. Every time an app saves it as a JPG again, the encoder throws away a little more detail. A PNG stores pixels exactly, so it is the safer place to park an image while you crop, annotate or retouch it over several sessions.
Some apps, templates and upload forms also simply ask for a PNG. This page rewrites your photos in that format without sending them anywhere. One honest warning up front: the PNG keeps the photo exactly as it is now, compression marks included, and it will be a lot bigger. The guide to JPG, PNG, WebP and AVIF explains why.
- 1
Add your JPGs
Drop photos on the panel or pick them from your device. You can add a whole folder’s worth; each file is checked by its contents, so a misnamed file still opens.
- 2
Choose optimization and metadata
Leave OxiPNG optimization on for smaller PNGs, or switch it off when you want speed. Then decide whether to strip all metadata or only the GPS location.
- 3
Download the PNGs
Save each PNG on its own, or grab everything as one zip. Duplicate names get a -2 or -3 suffix so nothing is overwritten.
What this tool does
- JPG in, lossless PNG out
- Also reads PNG, WebP, AVIF and HEIC
- OxiPNG size optimization, on by default
- Many files at once, zipped for download
- Sideways phone photos saved upright
- Embedded color profile carried over
- Strip all metadata, or only the location
Worked example: one photo, three sizes
We converted our 1600 × 1200 test photo (a synthetic outdoor scene, 398,618 bytes as a JPG) with the same codecs this page uses, run in Node.
| Version | Size |
|---|---|
| Original JPG | 398,618 bytes (399 KB) |
| PNG without optimization | 2,422,351 bytes (2.42 MB) |
| PNG with OxiPNG (default) | 1,222,810 bytes (1.22 MB) |
| Raw pixels, uncompressed | 7,680,000 bytes |
The optimized PNG is about 3.1 times the size of the JPG, and OxiPNG cut the plain PNG roughly in half. We decoded the PNG again and compared it with the decoded JPG: every pixel matched. That is the deal in one line: nothing is lost, but nothing is gained either, and you pay for it in bytes. (1 KB = 1,000 bytes.)
What happens when a JPG becomes a PNG
The MozJPEG decoder, compiled to WebAssembly and running in a background worker, turns the JPG into a grid of red, green, blue and alpha values. If the camera stored the photo sideways with an orientation tag, that rotation is applied to the pixels now, so the PNG looks right in every viewer.
Those pixels are then written as a PNG, which uses lossless deflate compression (the W3C specification requires that filtering and compression preserve all information). With optimization on, OxiPNG tries different row filters and compression settings and keeps whichever produces the smallest file. The pixels stay identical; only the packing changes. The embedded color profile, if the JPG has one, goes into the PNG too.
When a PNG is the right container, and when it isn’t
Good reasons: you will edit and re-save the picture several times; a tool or print template only accepts PNG; you plan to cut out the background later in an editor and need a format that can hold transparency.
Weak reasons: hoping the photo will look sharper, or preparing it for a website or an email. For those, a PNG of a photo is just heavier. Shrink the JPG with the image compressor instead, or make a modern web copy with the WebP converter. When the editing is done, the PNG to JPG converter takes you back to a shareable file.
Good to know
- Expect a bigger file. Photos usually grow several times over as PNG, as the worked example shows.
- No detail comes back. Blockiness or blur already in the JPG is copied faithfully into the PNG.
- No transparency is added. A JPG has no alpha channel, so the PNG is fully opaque until you remove a background in an editor.
- Optimization takes time. In our test OxiPNG needed about 2.2 seconds against 37 milliseconds for a plain save. Switch it off for large batches on a phone if speed matters more than size.
- Very large photos are capped. Above 50 megapixels on a computer (24 on a phone), the page offers to resize to 6000 px on the long edge, or to skip the file.
What happens to your files
Processed on your device. Your photos are never uploaded. PixWrench’s code runs on your device. We don’t receive your files, file names or their contents.
Your JPGs are decoded and rewritten by WebAssembly code inside this tab. The finished PNGs are handed to your browser’s own download, and the zip is assembled in memory on your device. Only your settings, such as the optimization switch, are remembered in local storage; the photos themselves are not kept once you close the page.
Related tools and guides
Questions people ask
Does converting JPG to PNG improve quality?
No. The PNG holds exactly the pixels the JPG decodes to. It only stops further losses from future saves.
Why is my PNG so much bigger than the JPG?
JPG discards detail the eye barely notices, while PNG stores every pixel exactly. Our 399 KB test photo became a 1.22 MB PNG even after OxiPNG optimization.
Will the PNG have a transparent background?
No. JPG files can’t store transparency, so the PNG starts fully opaque. You can erase the background afterwards in an image editor.
Can I convert lots of JPGs at once?
Yes. There is no file-count limit; your device’s memory is the practical limit. Download the results one by one or as a zip.
Is the location from my phone photo kept?
Only if you want it. Pick “Remove all metadata”, or “Remove location, keep the rest” to keep the date and camera details. The EXIF viewer shows what a photo contains.
Can I turn the PNG back into a JPG later?
Yes, with the PNG to JPG converter. Do it once, at the end of your editing, to keep losses to a single save.
Sources and review
- W3C — Portable Network Graphics (PNG) Specification (Third Edition)
- MDN — Image file type and format guide
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