Guides
What the tools do, explained once, so the next refused upload makes sense.
- How image compression works, and how to land exactly under a size limit
What the quality slider actually changes, why pixel size matters more than quality below 50 KB, and how a search finds the best file under a limit.
6 minutes, updated 2026-11-07
- JPG vs PNG: which one to use, and when converting helps
The practical differences between JPG and PNG, with file-size comparisons for photos, screenshots and logos, and the cases where converting is worth it.
5 minutes, updated 2026-11-07
- WebP: when it saves you a third of the bytes, and when a form will reject it
What WebP is, how much smaller it really is, which browsers and sites accept it, and how to convert to and from it without losing quality.
5 minutes, updated 2026-11-07
- How many pixels is 3.5 × 4.5 cm? Photo sizes, DPI and what portals actually check
Convert centimetres and inches to pixels at any DPI, with a table of common ID photo sizes, and why a form that says cm is really asking for pixels.
4 minutes, updated 2026-11-07