toolready. Image Compressor

Image Compressor

Compress images with a live quality slider. Before/after size comparison.

What this does

Shrinks an image file by re-encoding it at a quality you choose, and shows you the result while you decide. Drop a file and it is compressed straight away with the defaults — JPG output at quality 75 — with the original and the compressed version side by side, each labelled with its byte size and the percentage saved (or, in red, the percentage gained if a setting makes the file bigger). Drag the quality slider and the right-hand preview and the size readout update as you go. Compression runs on a canvas in your own browser; the picture is never uploaded, and the pixel dimensions are left exactly as they were.

How do I compress an image without losing quality?

  1. Drop or choose your file. Supported inputs are PNG, JPG, WebP, AVIF, GIF, BMP, SVG, ICO and HEIC/HEIF, up to 50 MB.
  2. Look at the compressed preview at 75. If you can't tell the difference, try lower; if you can, nudge it up. Changes apply a fraction of a second after you stop dragging.
  3. Try WebP in the output menu and compare the size figure against JPG at the same quality.
  4. Click Download. The file is named after the original with -compressed and the new extension, e.g. hero-compressed.webp.

Which output format should I choose?

  • JPG (the default) — for photographs. No transparency: any see-through area in a PNG or GIF source is filled in.
  • WebP — also lossy with the slider, often smaller than JPG for the same look, and it keeps transparency. Compare the two size readouts for your particular image rather than assuming.
  • PNG — lossless. The quality slider has no effect on it, so if a PNG comes out larger than the input there is nothing to tune; that input was probably already a well-optimised PNG or a JPG that PNG cannot represent compactly.

Why is my compressed file bigger than the original?

Because the tool always decodes to raw pixels and re-encodes from scratch, it can't do better than the browser's encoder at the quality you set. A JPG that was already saved at quality 60 and re-saved here at 75 will grow — the readout turns red with a plus sign to make that obvious. Drop the slider until the number goes green, or accept that the source was already tight. The same applies to PNG output from a small JPG source.

What happens to EXIF and other metadata?

It is discarded. A canvas re-encode writes only image data, so camera model, timestamps and GPS coordinates are not in the downloaded file. For most web use that is a bonus (metadata can add tens of kilobytes and leaks location); if you want to see what is being dropped first, run the file through the EXIF viewer.

Should I resize before compressing?

Often, yes. This tool keeps the original dimensions, so a 4000-pixel photo destined for a 800-pixel slot is still carrying five times the pixels it needs however hard you compress it. Run it through the resizer first, then bring the result here. If you only need to change format without fiddling with a slider, the converter does that in batches of up to 20.