Choosing an image format is not about which is "best" — it is about matching the format to the picture. Use JPG for a logo and you get a fuzzy, halo-ringed mess; use PNG for a photo and you get a file five times larger than it needs to be. This guide explains what each format is genuinely good at, then gives you a rule you can apply without thinking.
The one question that decides it
Before comparing anything, answer this: is the image a photograph, or a graphic?
- A photograph (or any image full of smooth gradients and fine texture) wants a lossy format — JPG, WebP, or AVIF — because they discard invisible detail and save enormously.
- A graphic (logo, screenshot, icon, line art, anything with flat colours, sharp edges, or transparency) wants a lossless format — PNG, WebP-lossless, or SVG — because lossy compression smears crisp edges.
Ninety per cent of format decisions fall out of that one question. The rest is choosing which lossy or which lossless format.
The formats, one by one
JPG / JPEG — the universal photo format. Lossy, ~30 years old, supported by literally everything. Excellent for photographs; poor for anything with sharp edges (it adds "ringing" halos) and it has no transparency. Still the safest default when universal compatibility matters.
PNG — the graphics and transparency format. Lossless, so logos, screenshots, and UI stay pixel-perfect, and it supports a full alpha (transparency) channel. The trade-off: PNG files of photos are huge. Use it for graphics and anything that needs a transparent background, not for photos.
WebP — the modern all-rounder. Google's format does both lossy and lossless, supports transparency and animation, and is roughly 25–35% smaller than JPG (lossy) or PNG (lossless) at the same quality. Supported by every current browser. For most websites in 2026, WebP is the smart default — you get JPG-beating photos and PNG-beating graphics from one format.
AVIF — the efficiency champion. Based on the AV1 video codec, AVIF compresses even harder than WebP — often another 20–30% smaller — with better colour, HDR, and fewer artefacts at low bitrates. The cost: slower to encode, and while browser support is now broad, it is not quite universal. Use it when squeezing every byte matters and you can provide a fallback. (Deep dive: WebP vs AVIF.)
GIF — legacy animation only. 256 colours max, poor compression, but universally supported for short animations. For anything new, an animated WebP (or a video) is smaller and looks far better.
SVG — for logos and icons, not photos. SVG is not pixels at all; it is instructions (vector maths), so it scales to any size with zero quality loss and tiny file sizes — perfect for logos, icons, and simple illustrations. It cannot represent a photograph. (See SVG to PNG when you need a raster copy.)
Side-by-side
| Format | Type | Transparency | Best for | Avoid for |
|---|---|---|---|---|
| JPG | Lossy | ✗ | Photographs, universal compatibility | Logos, text, screenshots |
| PNG | Lossless | ✓ | Logos, screenshots, transparency | Photographs (huge files) |
| WebP | Both | ✓ | Modern web — photos and graphics | Very old software |
| AVIF | Lossy (mostly) | ✓ | Maximum compression, hero images | When you need a guaranteed fallback |
| GIF | Lossless | 1-bit | Legacy animation | Anything new (use WebP) |
| SVG | Vector | ✓ | Logos, icons, illustrations | Photographs |
HEIC — the format your iPhone actually uses
There is a seventh format worth knowing because it lands on your devices whether you chose it or not: HEIC (High Efficiency Image Container), the default on modern iPhones. It compresses roughly twice as efficiently as JPEG at the same quality, which is why your phone can store thousands of photos. The catch is compatibility: Windows, many web forms, older software, and lots of websites cannot open HEIC. The usual fix is to convert HEIC to a universal format on the way out — HEIC to PNG or JPG — so the photo opens everywhere. Convert to JPG to keep it small, or PNG if you need it lossless for editing.
Transparency: the thing only some formats do
A surprising number of format headaches come down to one feature: a transparent background (the alpha channel). Only some formats support it, and picking a format that does not is why a logo suddenly gains an ugly white box:
- PNG — full 256-level transparency. The reliable choice for logos and graphics that sit on coloured backgrounds.
- WebP — full transparency and smaller files than PNG. The modern pick.
- SVG — transparent by nature (it only draws the shapes you define).
- GIF — only 1-bit transparency (a pixel is either fully opaque or fully clear), so edges look jagged.
- JPG — no transparency at all. Save a logo as JPG and the see-through areas become solid white or black.
So the moment an image needs to sit on top of something else, your format list shrinks to PNG, WebP, or SVG. If you are trying to create transparency (cut out a background), that is an editing step first — see making an image transparent and removing backgrounds — and then you save the result as PNG or WebP to preserve it.
A rule you can apply in one second
- Photo for the web? → WebP (or AVIF with a JPG fallback). Plain JPG if compatibility is paramount.
- Logo, icon, or illustration? → SVG if you have the vector; otherwise PNG (or WebP-lossless).
- Screenshot or anything with text? → PNG or WebP-lossless — never JPG.
- Needs a transparent background? → PNG or WebP (never JPG).
- Short animation? → animated WebP, or a real video.
Converting between them
Because these are just different ways of encoding the same pixels, converting is quick and — for the lossless directions — quality-free. Common moves: PNG to JPG (shrink a photo saved as PNG), convert anything to WebP (modernise for the web), and HEIC to PNG/JPG (open iPhone photos anywhere). Two cautions: converting to a lossy format (e.g. PNG→JPG) discards detail permanently, so keep the original; and converting a JPG to PNG does not recover quality — it just makes a bigger file. Use the image converter, or the direct routes like JPG to WebP and PNG to WebP, all in your browser.
Key takeaways
- Decide photo vs graphic first — that picks lossy vs lossless.
- WebP is the smart modern default: smaller than JPG for photos, smaller than PNG for graphics, with transparency and animation.
- AVIF compresses hardest — use it with a fallback when every byte counts.
- PNG for transparency and crisp graphics; JPG for maximum compatibility; SVG for logos and icons.
- Converting to a lossy format is one-way — keep your original.