Quality Levels Explained

The q_ parameter controls compression strength on a 1-100 scale. Here's what each range actually looks like:

  • q_90-100 — near-lossless. 10-20% file reduction. Pixel-perfect for printing and archiving.
  • q_70-85 — the sweet spot for web. 40-60% reduction with no visible quality loss on screens. This is what most websites use.
  • q_40-60 — heavy compression. 70-80% reduction. Fine for thumbnails and previews. Visible artifacts if you zoom in.
  • q_1-30 — extreme compression. Tiny files but obvious quality loss. Only for placeholder images or loading skeletons.

Default quality is 80 if you don't specify a q_ parameter.

The WebP Trick

Adding f_webp to any image URL converts it to WebP format, which is 25-35% smaller than JPEG at the same visual quality. It's the single most effective way to reduce file size.

# Original JPEG: ~500 KB
/img/photo.jpg

# Same image as WebP: ~350 KB
/img/f_webp/photo.jpg

# WebP + quality reduction: ~200 KB
/img/q_75,f_webp/photo.jpg

WebP is supported in all modern browsers (Chrome, Firefox, Safari, Edge). For older browser compatibility, use the original JPEG as a fallback.

Progressive JPEG Loading

The fl_progressive flag makes JPEGs load gradually — first a blurry full preview, then sharpening to final quality. This gives users something to see immediately instead of a blank space loading from top to bottom.

/img/q_80,fl_progressive/photo.jpg

Progressive JPEGs are usually slightly smaller than baseline JPEGs too. There's no quality cost — it's purely a loading strategy change.

Combining Compression Techniques

Stack multiple parameters for maximum compression:

# Step 1: Quality only → ~60% reduction
/img/q_75/photo.jpg

# Step 2: + WebP → ~75% reduction
/img/q_75,f_webp/photo.jpg

# Step 3: + Resize → ~85% reduction
/img/w_1200,q_75,f_webp/photo.jpg

# Step 4: + Progressive → ~86% reduction
/img/w_1200,q_75,f_webp,fl_progressive/photo.jpg

A 5 MB photo can often be reduced to under 200 KB with these combined techniques — without visible quality loss on a screen.

Recommended Settings by Use Case

  • Blog/website images: w_1200,q_80,f_webp
  • Social media posts: w_1080,q_85 (keep JPEG for compatibility)
  • Email newsletters: w_600,q_70 (small files for fast loading)
  • Thumbnails/previews: w_400,q_60,f_webp
  • Print-quality archive: q_95 (minimal compression)

Upload supports JPG, PNG, GIF, and WebP up to 50MB. Drag & drop or paste from clipboard.

Open Compress Tool →