Online Image Compressor
Compression happens in your browser — the image is never uploaded to a server or stored anywhere.
About the tool: online image compression
This tool reduces the weight of a photo or a picture so that a form, an email or a website will accept it. It helps every time you see "file is too large": submitting documents to government services, classified ads, a CV, an email attachment, an upload to a site. There are no third-party ads, no limits on the number of files and no sign-up.
Processing happens entirely in your browser — the image never goes to a server and is not stored anywhere. For photos this matters: they often carry documents, faces, plate numbers and addresses.
Key benefits of the tool:
You see the result at once: the original and the compressed version sit side by side, with the weight of each and how many percent you saved. You do not have to download the file to find out whether it worked.
Two levers instead of one: quality and the longest side. When quality alone is not enough, reducing the dimensions cuts the weight several times over.
Format of your choice: keep the original one or re-encode to WebP, JPEG or PNG. The result downloads with a single button.
What do the settings mean?
1. Format
The format decides both the weight and where the file will open afterwards:
Same as original: the safe default. The file keeps its type, so it will certainly be accepted wherever the original one was.
WebP: at the same quality it weighs roughly a quarter to a third less than JPEG. Every modern browser understands it — but some older programs and government portals do not. Pick it when the file goes online.
JPEG: the most compatible format for photos. It has no transparency, so a transparent background turns white.
PNG: compresses losslessly, so the quality slider has no effect on it. Needed for screenshots, diagrams and logos with a transparent background. For photos it produces the largest file — that is normal, this is how the format works.
2. Quality
The slider works only for JPEG and WebP — it is a trade-off between weight and sharpness. The default is 80%: the difference from the original is barely visible to the eye, while the weight drops several times over.
90–100%: for print or when the photo will still be edited. The gain in weight is small.
70–85%: the working range for websites, ads and emails. Artefacts are not noticeable.
30–60%: when you have to fit a hard limit. Noticeable artefacts appear on flat fills and text — watch the preview.
3. Longest side
It caps the larger side of the image, the smaller one is recalculated automatically, so the proportions are not distorted. This is the most effective way to cut the weight: a phone photo often has 4000 px on its long side, while 1920 px is enough for a screen or a document.
Keep as is: leaves the dimensions untouched, only quality does the work.
2560 and 1920 px: with room to spare for large screens and full-screen viewing.
1280 and 800 px: for an email attachment, avatars or pictures inside text.
How to reach the weight you need?
First reduce the longest side, and only then lower the quality. Half the dimensions give roughly four times fewer pixels — that is almost always more effective than the slider.
You do not fit the limit: switch the format to WebP, if whoever accepts the file supports it.
A screenshot or a diagram: stay on PNG. In JPEG a grey halo appears around text and lines.
The result is larger than the original: this happens when the source file is already compressed or when you re-encode a photo to PNG. The tool warns about it — change the format or the quality.
And a warning about quality: compression is irreversible. Every repeated lossy save damages the picture further, so always compress from the original, not from an already compressed copy.