Converting an already-compressed JPEG to PNG in the hope of recovering quality, which only multiplies the file size.
File formats
PNG
Also called portable network graphics, .png or png file. Here is what it means, when it changes what you export, and what people get wrong.
File formatsRuns on your deviceUpdated 10 August 2026
The short answer
PNG (Portable Network Graphics) is a lossless image format that stores every pixel exactly as it was saved and supports full alpha transparency. It suits logos, screenshots, text and graphics with hard edges, and anything that needs a transparent background, but it produces large files for photographs.
Updated
The short version
PNG at a glance
| Quick fact | Detail |
|---|---|
| Compression | Lossless, filtering plus DEFLATE |
| Transparency | Yes, full alpha channel |
| Bit depth | 1 to 16 bits per channel |
| Animation | Yes, APNG, official since 2025 |
| Colour spaces | RGB, greyscale, indexed. No CMYK |
| Best for | Logos, screenshots, text, cut-outs |
Slide the table sideways to see every column.
How does PNG stay lossless?
PNG compresses in two stages. First it applies a filter to each row of pixels, predicting each pixel from its left and upper neighbours and storing only the difference. Then it runs the filtered data through DEFLATE, the same general purpose compressor used inside ZIP files. Both stages are perfectly reversible, so decoding a PNG returns the exact pixel values that went in.
That is what lossless means in practice. You can open a PNG, save it, and repeat that a hundred times without the pixels drifting. JPEG cannot do this, because it discards detail on every encode. The trade is size: DEFLATE is very good at flat colour, repeated patterns and hard edges, and quite poor at the fine, noisy gradients that make up a photograph.
What do PNG-8, PNG-24 and PNG-32 mean?
Those names come from image editors, not from the specification. They are shorthand for combinations of colour type and bit depth.
| Label | Bits per pixel | Colours | Transparency |
|---|---|---|---|
| PNG-8 | 8 | Up to 256, from a palette | Palette entries can be fully or partly transparent |
| PNG-24 | 24 | About 16.7 million | None |
| PNG-32 | 32 | About 16.7 million | Full 8-bit alpha channel |
The specification itself is broader. It defines greyscale, truecolour, indexed and alpha-bearing colour types at bit depths from 1 to 16 bits per channel, so a 16-bit-per-channel PNG with a 16-bit alpha channel is entirely valid. What PNG does not offer is CMYK, which is why print workflows reach for TIFF or PDF instead.
What changed in the 2025 PNG specification?
The PNG Specification Third Edition became a W3C Recommendation in June 2025, the first substantial revision since the Second Edition in 2003. Three additions matter day to day.
- APNG animation is now part of the official specification rather than a widely implemented extension bolted on the side.
- HDR is supported through the
cICPchunk, which tags an image with a coding-independent code point so a display knows to render it in a wide-gamut, high dynamic range space. - EXIF metadata (camera, lens, orientation, copyright) now has an official chunk instead of being carried in private ones.
Older software still opens new PNG files, because the format was designed so that decoders skip chunks they do not recognise.
When is PNG the wrong choice?
For photographs. A 3000 px product shot saved as PNG can easily be five to ten times the size of the same image as a good quality JPEG or WebP, with no visible benefit, because the eye cannot see the detail PNG is spending all those bytes preserving. That matters when platforms cap upload sizes: Etsy warns that files over 1 MB may fail to upload, and Walmart Marketplace caps images at 1 MB each.
Transparency is also not universally honoured. Etsy does not support transparent PNG files, and transparent areas appear black in listings, so a cut-out product needs a flattened white background before upload rather than an alpha channel.
How do you make a PNG smaller without losing quality?
Work through these in order, because the first one usually dominates everything else.
- Reduce the pixel dimensions. Halving width and height removes roughly three quarters of the data. Nothing else comes close.
- Reduce the colour count. Flat graphics, icons and screenshots often convert from truecolour to a 256-colour palette with no visible change and a large drop in size.
- Strip metadata. Colour profiles, EXIF blocks and editor thumbnails can add tens of kilobytes to a small image.
- Convert to lossless WebP. It uses the same idea more efficiently and is typically noticeably smaller than PNG for the same pixels.
All four are lossless in the sense that matters, and any converter that runs the encode locally, Photomop's included, avoids uploading the original anywhere.
What people get wrong about png
Each one is a real failure mode, not a style preference.
Uploading a transparent PNG to Etsy, where the transparent areas render as solid black.
Choosing PNG for full-page product photography and then hitting a marketplace file size cap.
Assuming PNG-24 carries transparency; the variant with an alpha channel is PNG-32.
Questions people ask
PNG, answered
The follow-up questions people search for once they have the definition.
Does PNG lose quality when you save it again?
No. PNG compression is fully reversible, so re-saving returns the same pixel values every time. The only way to lose quality is to change the image itself, by resizing it, reducing it to fewer colours, or converting it to a lossy format such as JPEG.
Is PNG or JPEG better for product photos?
JPEG for photographs, PNG for anything with transparency, text or hard edges. A photo saved as PNG is far larger with no visible gain. The exception is a cut-out product image you plan to place on different backgrounds, which needs PNG's alpha channel.
Can a PNG file be animated?
Yes, through APNG, which became part of the official PNG specification in the 2025 Third Edition. APNG handles smooth transparency and full colour, both of which GIF struggles with. Not every older tool writes or reads APNG, so check your target platform first.
Why is my PNG so much bigger than the JPEG version?
Because PNG keeps every pixel and JPEG throws most of them away. Photographic detail is close to random from a compressor's point of view, so lossless coding cannot shrink it much. On flat graphics the gap reverses and PNG often wins.
Does PNG work for professional printing?
Only for RGB workflows. PNG has no CMYK colour type and no support for spot colours or separations, so commercial printers usually ask for TIFF or PDF. For home and office printing, or for online print services that accept RGB, PNG is fine.
Same cluster
More from the glossary
Neighbouring entries, so every term in the set is one hop from every other.
PPI
PPI, pixels per inch, states how many image pixels are packed into each inch of output.
Pixelation
Pixelation is when individual pixels become visible as square blocks because an image is shown larger than its pixel count supports.
Product photo
A product photo is an image made to sell a specific item, showing it clearly enough that a buyer can judge what they are getting.
From the studio
Tools that do this
Each one runs on your own device, so the photo stays where it is.
Sources
Where the facts on this page come from. Every link opens the specification, standard or documentation the claim was read at.
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Now do it to a photo
Photomop is a photo studio that runs on your own device. Resize, crop, compress, convert, batch edit, remove a background and change one all work in the browser tab you are reading this in, at full resolution and with no watermark. The on-device page shows you how to check that the photo stays put.