How to Compress an Image Without Losing Too Much Quality
Updated · 4 min read
Every image you compress loses some data. The goal is to lose only data nobody notices. With the right settings, a 4 MB phone photo can become a 300 KB file that looks the same on screen. Here’s how to get there.
1. Resize before you compress
The biggest saving usually comes from dimensions, not quality. A modern phone takes photos of about 4000 × 3000 pixels, but a website or email rarely displays them wider than 1200–1920 pixels. Halving the width and height leaves a quarter of the pixels, and roughly a quarter of the file size, with no visible loss at the size it’s shown.
Use the image resizer to set a width, or set a maximum width directly in the image compressor.
2. Choose the right format
- Photos: JPG or WebP. Both use lossy compression designed for photographs. WebP is usually 25–35% smaller than JPG at the same visual quality.
- Graphics with text, logos and screenshots: PNG or high-quality WebP. Lossy JPG compression creates blurry halos around sharp edges.
- Transparency: PNG or WebP. JPG can’t store transparent areas.
A photo saved as PNG is often 5–10 times bigger than it needs to be. Converting it with the PNG to JPG converter is often the single biggest improvement.
3. Pick a sensible quality setting
For JPG and WebP, quality is a trade-off. As a rule of thumb:
| Quality | Result |
|---|---|
| 90–95% | Visually identical; for printing and editing |
| 75–85% | Hard to tell apart on screen; best balance for most uses |
| 60–70% | Slight softness in fine detail; good for thumbnails |
| Below 50% | Visible blocks and smudging, especially in skies and skin |
Going from 95% to 80% often halves the file size, while going from 80% to 60% saves much less. That’s why the middle of the range is the sweet spot.
4. Don’t compress the same image repeatedly
Each time a JPG is opened, edited and saved again, it loses a little more quality. Keep your original file, and always compress from the original rather than from an already-compressed copy.
5. Check the result at the size it will be viewed
Zooming to 400% will reveal compression in any image. What matters is how it looks at its real display size. Open the compressed file next to the original at normal size. If you can’t tell which is which, the compression is fine.
When you need a specific file size
Upload forms often set a hard limit. Instead of trying quality levels by hand, use Compress Image to 100KB or Compress Image to 50KB. They search for the highest quality that fits, and reduce dimensions only when necessary.