Compress Image

About the Image Compressor

This shrinks image file sizes so they're faster to upload, email or put on a web page, without you needing photo software. Big camera photos and screenshots are often several megabytes; compressing them cuts that down while keeping them looking fine at normal viewing sizes. It's useful for meeting an upload size limit, speeding up a website, attaching photos to an email, or saving storage — and it tells you how much smaller the result is.

How it works

Your image is drawn onto an HTML canvas and re-encoded at a quality level you control (a slider), using the browser's built-in image encoders. Lower quality means smaller files. You can also choose the output format — JPG, WebP or PNG — and the tool shows the percentage size change compared with the original, flagging when a different format or lower quality would help. Everything happens on your device; nothing is uploaded.

Assumptions and behaviour

• JPG and WebP are lossy and respond strongly to the quality slider — WebP usually gives the smallest file at a given quality.
• The size-change readout compares the output against your original so you can see the saving at a glance.
• Re-encoding through the canvas strips metadata (such as EXIF, including any GPS location) — a privacy bonus, though it also removes camera info you might have wanted to keep.
• Image dimensions are unchanged; this reduces file size by compression, not by resizing.

Limitations

• PNG is lossless, so the quality slider barely shrinks it. For big savings on a PNG photo, convert it to JPG or WebP — the tool nudges you toward this when PNG output ends up larger.
• Compression is lossy for JPG/WebP, so pushing quality too low introduces visible blocky or blurry artefacts; find the balance where it still looks good.
• Re-compressing an already-compressed JPG loses a little more quality each time — compress from the best original you have.
• It compresses one image at a time; for many files at once use the Bulk Image Compressor.

Privacy

Compression runs entirely in your browser with the Canvas API. Your image is never uploaded or stored — and re-encoding removes embedded metadata like location.