PNG vs JPG vs WebP vs AVIF: Which Image Format Should You Actually Use?
A practical comparison of PNG, JPG, WebP and AVIF — what each format is genuinely good at, what it costs you, and how to pick one in under ten seconds.
Updated August 11, 20265 min read
Choosing an image format is usually a thirty-second decision that people spend either zero seconds or thirty minutes on. The short version: photographs go to JPG or WebP, graphics with flat colour and sharp edges go to PNG or WebP, anything that needs transparency rules out JPG entirely, and AVIF wins on size when you can afford slightly slower encoding. The rest of this guide explains why, and where each of those rules breaks.
The one distinction that decides most cases
Every format here falls into one of two camps. Lossy formats (JPG, and WebP/AVIF in their usual mode) throw away detail the eye is unlikely to notice, and get enormous size savings for it. Lossless formats (PNG, and WebP/AVIF in lossless mode) reproduce every pixel exactly, and pay for that in file size.
This maps cleanly onto content. Photographs are full of gradual tonal variation, so discarding some is invisible. Screenshots, logos and diagrams are full of hard edges, and lossy compression makes hard edges fuzzy in a way that is instantly obvious. That is the whole rule: smooth content wants lossy, sharp content wants lossless.
The four formats compared
| Format | Best for | Transparency | Typical size vs JPG |
|---|---|---|---|
| JPG | Photographs, anything with gradients | No | Baseline |
| PNG | Screenshots, logos, line art, UI mockups | Yes | 3–10× larger on photos |
| WebP | Almost everything on the web | Yes | 25–35% smaller |
| AVIF | Photos where every kilobyte counts | Yes | 40–55% smaller |
Those figures are for photographic content at comparable quality. On flat graphics the ordering flips: a PNG of a simple logo beats a JPG of it outright, because runs of identical pixels compress almost to nothing while JPG spends bits inventing artefacts around the edges.
JPG: still the safe default
JPG is more than thirty years old and still the most universally accepted image format in existence. Every browser, every phone, every printing service, every upload portal and every ancient enterprise system takes it. If compatibility matters more than the last 30% of file size — and for uploads it does — JPG is the answer.
Its weaknesses are worth knowing. It has no transparency, so a logo saved as JPG gets a white box around it. It re-compresses destructively, so repeated editing and saving degrades it each time. And it handles sharp text badly, which is why a JPG screenshot of a code editor looks smeared while the PNG version is crisp.
PNG: for edges, not for photos
PNG's superpower is exactness plus an alpha channel. Use it wherever a pixel must stay the pixel you drew: logos on coloured backgrounds, UI screenshots, charts, icons, and any image you will edit again later, since re-saving costs nothing.
The classic mistake is saving a phone photo as PNG. The file balloons — often to five or ten times the JPG size — for a quality difference nobody can see. If you have inherited a folder of oversized PNG photos, running them through the PNG to JPG converter — one at a time on the free tier, whole folders with Pro — is usually the single largest storage win available. If you need to keep them as PNG for transparency reasons, the PNG compressor reduces the palette and strips metadata without changing format.
WebP: the sensible modern default
WebP does both jobs. It has a lossy mode that beats JPG by roughly a third at matched quality, a lossless mode that beats PNG by roughly a quarter, transparency support, and animation support. Browser support has been universal since 2020, which removes the only real historical objection.
For a website, converting your image library to WebP is one of the cheapest performance wins available — a third off every image, with no visible change. The caveat is outside the browser: some desktop software, print shops and upload forms still reject it. Hence "WebP for the web, JPG for uploads," not "WebP for everything."
AVIF: the biggest savings, with a catch
AVIF compresses harder than anything else in common use — commonly 40–55% below JPG, and it holds up unusually well at very low bitrates, where JPG turns blocky and AVIF merely goes soft. It also supports transparency, wide colour and HDR.
The catch is encoding cost and ecosystem maturity: AVIF takes noticeably longer to encode than WebP, and support outside browsers is still patchy. Use it where bandwidth genuinely matters and you control delivery — and stick with WebP or JPG for anything that has to travel through other people's software.
A ten-second decision tree
- 1Does it need transparency? If yes, it is PNG, WebP or AVIF. JPG is out.
- 2Is it a photograph? If yes, JPG for compatibility, WebP for the web, AVIF if size is critical.
- 3Is it a screenshot, logo, chart or line art? PNG for guaranteed sharpness, or lossless WebP for the same sharpness at a smaller size.
- 4Is it going into an upload form? JPG, unless the form names another format.
- 5Is it animated? WebP for quality and size, GIF only if the destination demands it.
Pick your format pair — JPG, PNG, WebP, AVIF, GIF or BMP — and convert on your own device. Files are never uploaded.
Convert an imageWhat about HEIC, TIFF and SVG?
HEIC is what modern iPhones shoot by default. It compresses better than JPG but is poorly supported outside Apple's ecosystem, which is why so many people need a HEIC to JPG converter before they can email a photo to someone on Windows. TIFF is a print and archival format — huge files, excellent fidelity, no place on a web page. SVG is not in this comparison at all because it is not a pixel format: it describes shapes mathematically, so it is the right choice for logos and icons whenever you have the vector source.
If you are unsure what you actually have — a file named .jpg is not always a JPG — the image analyzer reads the real format, dimensions and metadata straight from the file.
Frequently asked questions
Is WebP better than JPG?
For web delivery, yes — WebP produces roughly 25–35% smaller files at comparable quality and adds transparency support. For uploads to forms, printing services or older software, JPG is still safer because it is accepted everywhere.
Does converting PNG to JPG lose quality?
Yes, slightly, because JPG is lossy. On photographs the loss is invisible and the size saving is large. On screenshots and logos the loss is very visible — sharp edges get fuzzy halos — so keep those as PNG or convert to lossless WebP instead.
Should I use AVIF on my website in 2026?
It is a good choice for photo-heavy pages where bandwidth matters, since it typically halves JPG file sizes. Serve it with a WebP or JPG fallback for the small share of non-browser clients that still cannot decode it.
Which format is best for printing?
Use the highest-quality original you have — ideally TIFF or a maximum-quality JPG at full resolution. Never send a WebP or a heavily compressed file to a print shop; compression artefacts that are invisible on screen become obvious at print sizes.