A 4 MB photo can slow a page to a crawl. Compressing images is the single highest-impact optimization for most websites — and you can do it privately, in your browser, with the DevToolbox Image Compressor.
Lossy vs lossless
- Lossy (JPEG/WebP) — discards some visual data. Great for photos; can shrink 70–90% with little visible change.
- Lossless (PNG) — keeps every pixel. Best for screenshots, diagrams, and text.
How browser-based compression works
The compressor loads your image into a <canvas>, re-encodes it at the quality you choose,
and hands back a smaller file. Because it runs locally, the image never leaves your device.
Practical tips
- Start at 80% quality — most photos look identical but drop dramatically in size.
- Set a max width for web use (e.g. 1600px); huge dimensions waste bytes.
- Use JPEG for photos, PNG for graphics with sharp edges or text.
Compress first, upload second. A 200 KB image loads far faster than a 3 MB one — and your visitors notice.
How much can you save?
Typical results: a 3.2 MB photo → ~480 KB at 80% quality (≈ 85% smaller) with no visible loss. The compressor shows the exact before/after sizes so you can verify.
- Will my image look worse?
- At 80% quality, almost never for photos. Drop toward 60% only if file size matters more than perfection.
- Is my image uploaded to a server?
- No. Processing is 100% client-side; we never receive your file.