Your phone pulls in a 5 MB photo. Paste it into a blog, and the page now drags on every visit. The photograph didn't need to be 5 MB at all — it was just saved with far more detail than any screen can show.
The entire trick of photo compression is removing detail nobody can see. And the fastest way to do it is one habit: re-save at quality 80.
Why quality 80, specifically
Cameras commonly write JPEGs at quality 92–100 to preserve every pixel for editing. That is overkill for the web. Re-encoding the same image at quality 80 strips only the redundant data — the tonal variations your eye cannot resolve. In practice:
| Saved quality | Typical result for a 5 MB photo | Visible change |
|---|---|---|
| 95 (original) | 5.0 MB | baseline |
| 80 | ~0.9–1.5 MB | none on screen |
| 70 | ~0.6–1.0 MB | slight on edges |
| 50 | ~0.4–0.6 MB | visible artifacts |
Notice the gap between the first and second rows: a 5 MB file becomes about one MB with no perceptible loss. That one change can be most of your site's entire speed budget.
The one-settings workflow
- Drag the photo into the compressor and set the slider to 80.
- Drag the compare handle to scan skies and edges — there is no visible difference.
- For pure website delivery, toggle WebP next; it usually drops the file again below the JPEG result.
A quick mental rule: 80 for anything on a page, 90 only for images you will edit again, below 60 only for backgrounds and thumbs. If you manage a shop's catalog, our e-commerce sizing guide gives the exact per-slot targets.