Compress Image: Reduce Image File Size Without Visible Quality Loss
Large images slow down websites, get rejected by upload portals, and fill storage unnecessarily. This image compressor reduces JPG, PNG, and WEBP file sizes using intelligent quality reduction algorithms — all inside your browser, with no server upload.
How to compress an image
- Upload your image — JPG, PNG, or WEBP.
- Set the quality level — 80% is ideal for web use; 60% gives maximum size reduction with acceptable quality; 90%+ for print-quality output.
- Click Compress — compare the before/after file sizes displayed.
- Download the compressed image.
When to compress images
- Website and blog uploads — Large images dramatically slow page load times. Google PageSpeed and Core Web Vitals penalise heavy images in search rankings.
- Email attachments — Most email clients cap attachments at 10–25 MB. A portfolio of product photos can be shared easily after compression.
- WhatsApp and messaging — Messaging apps re-compress images automatically, often at low quality. Pre-compressing ensures your image looks exactly as intended.
- Google Forms and LMS platforms — Educational platforms like Moodle and Canvas limit upload sizes. Compress images before submitting assignments.
- E-commerce product images — Compressed product photos load faster and improve conversion rates without visibly affecting quality.
Understanding compression quality levels
90–100% quality: Minimal compression; suitable for printing and professional photography archives. Files remain large.
70–85% quality: The "sweet spot" for web use — visually indistinguishable from the original for most images at normal viewing sizes, with 40–70% size reduction.
50–65% quality: Noticeable compression artefacts at high zoom; suitable for thumbnails and social media previews where fine detail is not critical.
Below 50%: Significant quality loss; use only when maximum file-size reduction is more important than image fidelity.
JPG vs PNG compression behaviour
JPG uses lossy compression — each save reduces quality slightly in exchange for significant size savings. It works best for photos and images with gradients. PNG uses lossless compression — reducing size by eliminating redundant colour data without affecting appearance. PNGs with simple graphics, logos, and text benefit most from PNG compression. For photographic content, converting PNG to JPG often gives far greater size reductions than PNG compression alone.
Frequently asked questions
- How much can I reduce an image's file size?
- Typical reductions are 40–80% for JPG at 80% quality. PNG compression is less dramatic — usually 20–50% — because PNG is already a compressed format. Converting a large PNG photo to JPG at 80% quality can reduce size by 80–90%.
- Will anyone be able to tell the image was compressed?
- At 75–85% quality, most people cannot detect compression artefacts when viewing images at normal screen resolution. The difference is mainly visible when zooming in to 200%+ on areas with fine detail or sharp edges.
- Does compression affect transparency in PNG files?
- PNG compression preserves transparency. If you need transparent images, keep them as PNG rather than converting to JPG, which does not support transparency.
- Can I compress multiple images at once?
- Currently, the tool processes one image at a time. For batch compression of many images, desktop tools like Squoosh, ImageMagick, or Photoshop's Export for Web feature may be more efficient.
Related tools