LocalKit

Compress Images for Web

Set a file size target (default 200 KB) and the tool automatically finds the highest quality that fits — no manual slider tweaking. No upload, no sign-up.

Your files never leave your device. All processing happens in your browser.

KB

Google recommends images ≤ 200 KB for fast pages.

Output format
Drop an image here, or click to browseJPG, PNG, WebP or GIF

How to Compress an Image for Web

  1. Set your target size. The default is 200 KB, which keeps images fast on typical broadband. Lower it for bandwidth-sensitive contexts (e.g. 100 KB for mobile-first pages) or raise it for large hero images where quality matters more.
  2. Choose WebP or JPG. WebP is recommended — it produces smaller files at equal quality. JPG is better if you need broad compatibility with older tools.
  3. Add your image. Drag a file or click to browse. Loaded directly in the browser — nothing is uploaded.
  4. Click “Compress to ≤ X KB”. The tool runs a binary search to find the highest quality that keeps the file under your target. The result card shows the final size, quality used, and estimated load time.
  5. Download. If the result looks good, click Download to save it.

Why Image Size Matters for Web Performance

Images are consistently the largest assets on most web pages — often 60–80% of the total page weight. Oversized images slow down the Largest Contentful Paint (LCP), which is one of Google's three Core Web Vitals and directly influences search rankings.

Google PageSpeed Insights flags individual images above 200 KB as opportunities to improve. As a rule of thumb:

  • Hero / banner images: aim for 150–300 KB
  • Product photos: 80–150 KB
  • Thumbnails and card images: 20–60 KB
  • Icons and logos: under 10 KB (or use SVG)

If a photo cannot reach the target without visible quality loss, the most effective fix is to also reduce the pixel dimensions before compressing — an 800 × 600 photo at quality 80 is almost always smaller than a 4000 × 3000 photo at quality 20.

Frequently Asked Questions

Why 200 KB specifically?

Google's PageSpeed Insights flags images above 200 KB as a performance issue on many pages. At a typical 50 Mbps connection, a 200 KB image loads in about 32 ms — fast enough to avoid affecting Largest Contentful Paint (LCP), a Core Web Vitals metric that affects search rankings.

How does the auto-optimiser work?

The tool uses a binary search: it tries quality 47, then checks if the result is under your target. If it is, it tries higher (e.g. 68); if not, it tries lower (e.g. 26). After 8 iterations it has found the highest quality that fits within your chosen budget — without you having to drag a slider back and forth.

What if the compressed image is still above the target?

Some images — especially very large photos — cannot be squeezed below a target at any quality without severe visible degradation. In that case, the tool shows a warning and suggests reducing the pixel dimensions first using the Image Resizer, then running the result through this tool.

Should I use JPG or WebP for web images?

WebP is recommended for new web projects. At the same visual quality, WebP files are 25–35% smaller than JPG. All modern browsers (Chrome, Firefox, Safari 14+, Edge) support WebP. If you need to support very old browsers, use JPG.

Does this tool change the image dimensions?

No. It only adjusts the compression quality — pixel dimensions stay the same. If your image is 4000 × 3000 px and you need it to be 1200 × 900 px on the page, resize it first to reduce dimensions and file size together, then compress for the final file size target.

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