JPG vs PNG: Which format should you use and when?
A practical breakdown of JPG vs PNG - how they compress, when each one wins, and a decision table you can actually use.
If you’ve ever right-clicked an image and wondered whether to save it as JPG or PNG, you’re in good company. The difference looks trivial — three letters — but picking the wrong one can make your photos look blurry, inflate your website’s load time, or strip transparency off a logo.
Use JPG for photographs. Use PNG for graphics, text, screenshots, and anything that needs a transparent background.
That covers 95% of cases. If you want to understand why — and the edge cases where the rule breaks — read on.
How JPG compresses images
JPG (or JPEG — same thing) was designed in 1992 for one job: squeezing photographs into the smallest possible file size without most people noticing the quality loss. It uses lossy compression — it literally throws away image data that the human eye is less sensitive to.
The trick is that JPG understands a few things about how we see. We notice brightness more than colour detail, so JPG discards colour data first. We notice sharp edges on text and lines more than subtle tonal shifts in a sky, so JPG smooths those tonal areas. And every time you re-save a JPG, more data is thrown away — this is called generation loss.
The result: a typical 4000×3000 px photograph shrinks from ~36 MB uncompressed to around 2-5 MB as a JPG with very little visible quality loss. That’s why every smartphone camera saves to JPG by default.
How PNG compresses images
PNG was born in the mid-1990s specifically to replace GIF, and it uses lossless compression. Every single pixel of the original image is preserved exactly. Save a PNG, open it, save it again — nothing changes.
PNG achieves its savings differently. It looks for repeating patterns and encodes them once, so a solid red rectangle compresses very well. It supports an alpha channel — every pixel can be fully transparent, fully opaque, or anywhere in between. And it supports indexed colour (palettes) for small images where only a few colours are used.
This makes PNG excellent for anything that is drawn rather than photographed: UI elements, icons, logos, diagrams, screenshots of text. For a photograph, PNG produces a file 3-10× larger than an equivalent-quality JPG with no visible improvement.
Side-by-side comparison
| Feature | JPG | PNG |
|---|---|---|
| Compression type | Lossy | Lossless |
| Transparency | No | Yes (full alpha channel) |
| Best for | Photographs | Graphics, text, logos |
| File size (typical photo) | Small (1-5 MB) | Large (10-40 MB) |
| File size (typical logo) | Large (bloated) | Small |
| Quality loss on re-save | Yes, compounds over time | No, ever |
| Animation support | No | No (APNG is a rare exception) |
| Maximum colours | 16.7 million (24-bit) | 16.7 million + alpha (32-bit) |
| Released | 1992 | 1996 |
The decision tree
Still unsure? Ask yourself in order:
- Does the image need a transparent background? → PNG. This is non-negotiable. JPG cannot do transparency.
- Is it a photograph (camera output, people, landscapes, textures)? → JPG.
- Is it mostly flat colours, text, or sharp lines (logos, UI, diagrams, screenshots)? → PNG.
- Does it mix photography and overlays (a photo with text)? → Prefer PNG if the text must stay crisp; JPG if file size matters more.
- Will it be edited multiple times? → PNG. JPG degrades with every save.
When you’re converting JPG to PNG
There’s one thing to be aware of: converting JPG to PNG does not recover quality that was already lost. If your source JPG is compressed and blocky, the resulting PNG will be a pixel-perfect copy of that blocky image. PNG’s losslessness only preserves what’s already there.
Converting JPG to PNG makes sense when you want to add transparency to a JPG (you’ll need to edit out the background afterwards), when you’re about to edit the image multiple times and don’t want quality loss at each save, when you need to embed it in a format that requires PNG (Windows icons, some document formats, certain web UI libraries), or when you want maximum compatibility with screen readers and older browsers.
It rarely makes sense when the image is a photograph you’re just viewing — stick with JPG, it’s smaller. And don’t convert because you think PNG is “better quality” by default. For photographs it isn’t.
What about WebP and AVIF?
Both are newer formats that beat JPG and PNG on compression. WebP shaves 25-35% off JPG file sizes at equivalent quality and can do transparency. AVIF goes further still — roughly 50% smaller than JPG.
So why aren’t they everywhere? Two reasons. Compatibility: every browser, operating system, CMS, email client, and document format understands JPG and PNG. WebP is now broadly supported but still occasionally breaks in older tools. AVIF is even patchier. Tooling: designers, marketers, and non-technical users expect JPG and PNG. Giving someone a .webp file often leads to “what’s this?” emails.
Use WebP or AVIF when you control the delivery (your own website, image CDN). Stick to JPG or PNG when the file will be shared, emailed, or handed to a human.
Quick FAQ
Is PNG “higher quality” than JPG? Not automatically. PNG is lossless, which means it preserves whatever it was given. If you start with a JPG and convert it to PNG, you get a lossless copy of a lossy source — no improvement.
Can I convert PNG to JPG without losing quality? You’ll lose something (JPG is lossy) but at a 90%+ quality setting the difference is usually invisible. You will lose any transparency — JPG doesn’t support it and will fill transparent areas with white by default.
Why are my PNG files so huge? Probably because they’re photographs. A 4000×3000 photo as PNG is easily 20-40 MB. That’s PNG working correctly — it’s preserving every pixel. Save as JPG for photos.
Does the platform (Windows / Mac / web) change the answer? No. JPG and PNG are standardised and behave the same everywhere. The only format quirks are around newer standards (WebP, AVIF, HEIC).
If you need to convert a JPG to PNG right now — to prepare an image for transparent-background editing or to hand it to a designer — the JPG to PNG converter does it in your browser in about two seconds. Nothing is uploaded. Drop the file, download the result, done.