Image Compressor
Image & Video Tools
Compress JPG and PNG images in your browser with a live quality preview and before/after sizes. Free, private, no signup.
70–80% is visually lossless for most photos; go lower for hard size limits.
How this image compressor works
Drag the quality slider, hit compress, and this tool re-encodes your image as a JPEG at that quality — in your browser, with the before/after sizes shown so you can see exactly what you saved. No upload, no server, no watermark. The honest mechanics: JPEG compression is lossy, so you're trading invisible detail for dramatically smaller files — at 70–80% quality the difference is imperceptible for photos while the file often shrinks by half or more. PNGs get converted to JPEG in the process (that's where the savings come from), which means transparency becomes a white background — keep the PNG original if you need it.
Image compression tips
- 70–80% quality is the sweet spot for photos — visually identical, roughly half the size. Below 50% you'll start seeing blocky artifacts in gradients and skies.
- Chasing a hard limit like "under 100 KB"? Compress, check the result size, and nudge the slider down until you're under — the before/after readout updates every run.
- Screenshots and graphics with sharp text edges compress worse as JPEG — artifacts show around letters. For UI screenshots, resizing often saves more than compressing.
- Compressing a PNG converts it to JPEG and flattens transparency to white — that's usually fine for photos, wrong for logos. Keep logos as PNG.
- For web pages, compress *and* resize: a 4000px photo shown at 800px wastes far more bytes than any quality setting can save.
Related tools
Image Compressor — common questions
Latest questions readers ask us about this topic.
Is my image uploaded to a server?
No. The image is decoded, re-encoded and measured entirely in your browser, and the download comes from your device's memory. Nothing you compress here is transmitted or stored anywhere.
How much smaller will my image get?
Photos from phones typically shrink 40–70% at 75% quality with no visible difference. The exact number depends on how compressed the input already was — recompressing an already-tiny JPEG saves little, and the before/after readout will tell you honestly.
Does compressing reduce quality?
Yes — JPEG compression is lossy by definition, which is exactly why it saves so much space. At 70%+ quality the loss is invisible for photos. Anyone promising "compression with zero quality loss" at these ratios is describing something JPEG can't do.
What happens to transparent PNGs?
JPEG has no transparency, so transparent areas become white when compressed. That's the right trade for photos, the wrong one for logos and graphics with cutouts — keep those as PNG and shrink them by resizing instead.
Can I compress to an exact file size like 100 KB?
Not in one click — JPEG quality doesn't map linearly to bytes. The workflow that works: compress at 75%, read the result, adjust the slider and re-run. Two or three tries usually lands within a few KB of any target.
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