How to compress images without losing quality

Updated 2026 · ~6 min read

Large image files slow down websites, eat up storage, and are awkward to share. Compression solves this by reducing file size — but done carelessly it leaves photos blurry and blocky. This guide explains how to shrink images while keeping them looking clean.

Lossy vs lossless compression

There are two broad approaches. Lossless compression (used by PNG) reduces size without throwing away any image data, so quality is perfectly preserved — but the savings are modest. Lossy compression (used by JPG and WEBP) discards information the human eye is least likely to notice, achieving far smaller files at the cost of some detail.

For most photographs, well-tuned lossy compression is invisible to the eye while cutting file size by 70% or more. The trick is choosing the right quality level.

Choosing a quality level

Quality is usually expressed as a percentage. As a rule of thumb: 90–100% is near-indistinguishable from the original and best for important photos; 70–85% is the sweet spot for web images, balancing size and clarity; below 60% you start to see visible artifacts around edges and in flat areas. Our compressor shows the resulting file size live as you drag the slider, so you can find the lowest setting that still looks good.

Which format compresses best?

• WEBP usually produces the smallest files at a given quality and is supported by all modern browsers — the best default for the web.
• JPG is universal and great for photographs, though slightly larger than WEBP.
• PNG is lossless and the right choice for logos, screenshots, text, or anything needing transparency, but produces much larger photo files.

Tips for the best results

1. Always compress from the original, highest-quality file — re-compressing an already compressed image stacks artifacts.
2. Resize before compressing: if an image will display at 800px wide, shrink it first with the resize tool, then compress.
3. Use WEBP for the web, JPG when you need maximum compatibility.
4. Check fine detail and faces after compressing — they show artifacts first.

FAQ

Does compressing reduce image dimensions?

No. Compression reduces file size in bytes, not the pixel dimensions. To change dimensions, use a resize tool.

Is the process private?

Yes — our compressor runs entirely in your browser, so images are never uploaded.

Ready to try it? Open the image compressor.