Compress Image
Shrink PNG, JPG and WebP files and see the size you save, front and centre.
Free · No watermark · Private — your image never leaves your browser
Every level is encoded and measured up front, so you pick from actual file sizes and savings percentages instead of dragging a slider and hoping.
Even the smallest setting stays above the point where blocking and colour banding become obvious, so nothing you download looks visibly degraded.
PNG, JPG and WebP all go in, and you can change the output format mid-compression when a different one would compress your particular image better.
How it works
Image compression works by throwing away data your eyes were never going to notice. Photographs are full of it — subtle gradients in a sky, near-identical pixels across a wall — and a good encoder discards exactly that while leaving edges and detail intact. Drop a PNG, JPG or WebP in and you get several compression levels side by side, each showing its real file size and the percentage saved, so you're choosing from measured results rather than guessing at a quality slider. Everything is encoded on your own device, which means even confidential images never leave your machine.
- 1Drop your image onto the page, click to browse, or paste it straight from the clipboard.
- 2Compare the compression levels — each shows its resulting file size and how much it saved.
- 3Switch the output format if a different one suits the image better (WebP is usually smallest).
- 4Download the version you picked. Nothing was uploaded at any point.
Lossy and lossless are different tools
Lossless compression (PNG) reorganises data so it rebuilds pixel-for-pixel — safe, but limited, and re-saving an already-optimised PNG barely helps. Lossy compression (JPG, WebP) permanently discards information the eye is poor at detecting, which is why it achieves dramatically smaller files. The practical rule: photographs want lossy, because they're full of discardable noise. Screenshots, logos and flat-colour graphics want lossless, because their hard edges are exactly what lossy compression handles worst, producing halos around text.
Why dimensions often matter more than quality
A 4000-pixel-wide photo displayed in a 800-pixel column is carrying twenty-five times more pixel data than it can possibly show. Halving the width quarters the pixel count, and that usually beats any amount of quality-slider fiddling. Check what size the image is actually displayed at before reaching for heavier compression — if it's oversized, resizing is the change that costs you nothing visually.
Compression is not repeatable
Each lossy save discards data permanently, and re-compressing an already-compressed file discards more on top — generation loss. Artefacts compound and the image gets progressively muddier, particularly around edges. Always compress from the highest-quality original you have rather than from a file you compressed last week, and keep that original somewhere safe.
Frequently asked questions
How much smaller will my image get?
It depends entirely on the source. A large PNG photograph converted to WebP commonly drops 70 to 90 percent with no visible difference. A JPG already saved at 70 percent quality might only give up another 20 percent, because most of the redundancy is already gone.
Will compressing lose quality?
Technically yes for lossy formats, visibly no at sensible settings. Around 80 percent quality, the difference is essentially undetectable at normal viewing sizes while the file is far smaller. The visible failure modes — blocky squares, halos around text, banding in gradients — only appear well below the floor this tool allows.
Which format compresses best?
WebP, almost always, and it keeps transparency. JPG is close behind for photographs and is accepted everywhere. PNG only wins when you need lossless output or an alpha channel and the destination can't take WebP.
Can I compress to an exact file size?
Not to a precise kilobyte target, but each level displays its resulting size, so you can pick the largest one that fits under your limit. For a hard cap like an upload form, start from the smallest and work upward.
Is there a limit on how many images I can do?
No. There's no account, no daily cap and no watermark. Because the work happens on your device rather than our servers, volume costs us nothing.
Is my image uploaded anywhere?
No. Compression runs entirely in your browser using the Canvas API. The image never touches a network, which is why it works offline once the page has loaded.