Image Quality Settings Explained: What 30%, 50% or 80% Actually Do
Image Quality Settings Explained
When you export a JPG or WebP, tools ask for a "quality" between 1 and 100. People assume it's "how good will it look" — in reality it's a file-size/artifact trade-off, and 100 is rarely what you want.
What the number really means
Compression works by throwing away tiny details the eye struggles to notice (chroma, small gradients). Higher quality = keep more of those details = larger file. There's a steep curve:
- 90–100: nearly lossless. Files explode — rarely worth it unless you're archiving.
- 80–90: visually identical to the original to most people, 2–4× smaller.
- 60–80: the practical sweet zone for web. Almost invisible artifacts, big savings.
- 40–60: visible softness in gradients/shadows. Fine for thumbnails.
- below 40: blocky edges, smearing in skies and faces. Only for icons or extreme constraints.
Safe defaults per use-case
- Website image: 75–80% (WebP) or 80–85% (JPG)
- Email attachment: 70–75%, and keep the total under 2MB (see our email image guide)
- Social media: 80% — engagement disappears with ugly compression
- Under 20KB badge: drop to 50–55% with our 20KB preset
- Under 100KB / 200KB: 60–70% via our 100KB and 200KB guides
The only rule that matters
Shrink dimensions first, then lower quality. A 4000px image at 50% looks worse and weighs more than the same image resized to 1200px at 80%. Resizing to 1200×675 and exporting at 80% routinely lands sites ~100–200KB per image (resize guide).
How to use the Compress Image tool
- Drop your file — it never leaves your browser.
- Drag Quality until the preview and size readout look right to you.
- Use the Quick presets (Low/Medium/High/Maximum) to jump straight to known-good values.
- Choose JPG, PNG or WebP and download.
Our tool shows a live "after" preview, so instead of guessing percentages you *see* the artifact threshold for your specific photo.
The trap no one warns you about
Re-saving an already-compressed JPG compresses the artifacts *again* — "generation loss". Always keep your original and re-export from it. Compressing a 200KB JPG to 100KB twice gets you 100KB but with double the softness; doing it once from the original at 70% keeps it crisp.