Image format comparison
Four formats cover almost everything on the web. The right one depends on what's in the image, and for screenshots, the answer is usually PNG.
This is part of the reference hub. Four raster formats cover almost everything you'll capture or embed. The right choice depends on the content of the image, not preference.
At a glance
| Format | Compression | Transparency | Best for | Avoid for |
|---|---|---|---|---|
| PNG | Lossless | Yes (alpha) | Screenshots, UI, line art, text | Large photos (big files) |
| JPEG | Lossy | No | Photographs, continuous tone | Text, sharp UI edges |
| WebP | Both modes | Yes (alpha) | Web photos and graphics, smaller than JPEG/PNG | Maximum compatibility with old tools |
| AVIF | Lossy/lossless | Yes (alpha) | Best compression for web photos | Fast encoding; legacy support |
Why PNG is the screenshot default
A screenshot is mostly flat fills, hard edges, and rendered text, the worst case for JPEG, whose lossy compression smears blocky artifacts around exactly those edges. PNG is lossless, so text stays legible and UI lines stay crisp. The full reasoning is in PNG vs JPEG, and the symptom it prevents is covered in why a screenshot looks blurry.
When to reach for the others
- JPEG: photos, hero imagery, anything continuous-tone where a little loss is invisible.
- WebP: a smaller drop-in for web photos and graphics when you control the delivery.
- AVIF: best-in-class compression for web photos when encode time and broad tooling support aren't constraints.
For an image you'll hand to a coding agent, stay with PNG: it's lossless and the most universally readable. To inline a small image directly, see image to base64.
Frequently asked questions
Why is PNG best for screenshots?
Screenshots are flat color, sharp text, and crisp UI edges. PNG is lossless, so it keeps those edges clean. JPEG's lossy compression adds blocky halos around text, which is exactly the kind of detail a screenshot needs to preserve.
When should I use JPEG?
For photographs and other continuous-tone images, where lossy compression saves a lot of size with little visible loss. JPEG also has no transparency, so it's wrong for anything needing an alpha channel.
Are WebP and AVIF safe to use now?
Yes for the web. Both are supported across current major browsers. AVIF compresses best but encodes more slowly; WebP is a balanced middle ground. For a screenshot you're handing to a coding agent, plain PNG remains the most universally readable choice.
Capture your first review.
About a minute from open tab to a shareable URL your agent can ingest.
Start capturing