Image Compressor

Make an image file smaller without changing its dimensions. Move the quality slider, watch the file size change, and download when the trade-off looks right. Everything happens in your browser.

JPG, PNG, WebP or GIF. The file stays on your device.

Lower quality means a smaller file. Release the slider to re-compress.

Original size
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Compressed size
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Reduction
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Compression runs in your own browser using the Canvas API. Your image is never uploaded to KnowVixa or anywhere else.

How to Use

  1. Click Choose an image and pick a file. The original size appears straight away.
  2. Drag the quality slider. Release it and the image is re-compressed at that setting.
  3. Compare the three figures — original size, compressed size, and the percentage reduction — and look at the preview to check the image still looks acceptable.
  4. Click Download compressed image when you are happy.

Features

  • Live size comparison — before, after, and the percentage saved, all visible at once.
  • Visual check — a preview of the compressed result, so you judge quality with your eyes rather than a number.
  • Adjustable quality — anywhere from 10% to 100% in steps of 5.
  • Dimensions untouched — the image stays the same width and height; only the file size changes.
  • No upload, no wait — no queue, no file-size limit imposed by a server.
  • Works offline — once the page has loaded, compression needs no internet connection at all.

Frequently Asked Questions

What quality setting should I use?

For photos on a website, 70–80% is the usual sweet spot — a large size reduction with little visible difference. Below about 50% you will start to see blockiness in smooth areas like skies. Use the preview to decide rather than guessing.

Why does the output come out as a JPG?

JPG compression is what makes the file smaller, so the result is always saved as JPG regardless of what you put in. This means PNGs with transparent backgrounds will come back with the transparency filled in — if you need transparency, this is not the right tool.

Is this lossless compression?

No. This is lossy compression: it discards image data to save space, which is why the file gets so much smaller. The original file on your device is untouched, so you can always start again.

Why did my file get bigger instead of smaller?

It can happen if the original was already heavily compressed and you choose a high quality setting like 95%. Lower the slider and it will shrink.

Do I lose quality if I compress the same image twice?

Yes. Each pass discards more data, and the losses accumulate. Always compress from the original file rather than from a previously compressed copy.

Are my images uploaded anywhere?

No. The Canvas API in your browser does the work. Your image is read from your device, processed in memory, and given back to you as a download.

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