BrowserTools

Image Compressor

Shrink image file sizes, keep the quality

By Guga — BrowserTools maintainer, Tbilisi, Georgia Updated 2026-09-04
Free Private No uploads
What is Image Compressor?

Compression is a straight trade: fewer bytes, and some of the image goes with them. The useful question is where the line sits for your image, and the only honest way to answer that is to encode it at several settings and look. This gives you a quality slider from 10% to 100% with four presets at 50, 75, 85, and 95, plus an output format selector. Note what Auto does: a PNG input becomes WebP, everything else becomes JPG. That is the sensible default — WebP is a better encoder and keeps the alpha channel, whereas JPG has to flatten transparency onto white. There is no PNG output option, because writing PNG at a chosen quality is not a thing the format offers. One file per pass; the stats panel shows the saving in bytes and percent.

Compress images with a quality slider and instant before/after size comparison — JPG input stays JPG, and PNG input can be re-encoded to WebP for a much smaller file. Because compression runs in your browser, your photos are never uploaded anywhere.

Private Image Compressor In Your Browser

Image Compressor is processed locally with client-side JavaScript. Your files never touch a server, and there is no queue to wait in.

Step-by-Step

How to use Image Compressor

1

Drop a JPG, PNG, or WebP onto the Drop an image to compress area — one file per pass.

2

Set Output Quality with the slider or the 50% / 75% / 85% / 95% preset buttons.

3

Choose an output format from the dropdown: Auto (best for input), JPG, or WebP.

4

Read the Original / Compressed / Saved / Dimensions figures, then press Download compressed image.

Key Capabilities
  • Accepts JPG, PNG, and WebP inputs through one drop zone
  • Quality runs from 10% to 100% with one-click presets at 50%, 75%, 85%, and 95%
  • Output format can be forced to JPG or WebP, or left on Auto — which sends PNG to WebP and everything else to JPG
  • Reports original size, compressed size, saving in bytes and percent, and the pixel dimensions
Common Use Cases
  • A marketplace seller whose listings reject images above a size ceiling and needs each photo shrunk to fit.
  • A developer preparing screenshots for an issue report where every kilobyte of attachment matters.
  • A blogger reducing the weight of a post's images before it goes live on a slow mobile connection.
Clear Answers

Frequently Asked Questions

What does Auto do with my file?
A PNG is encoded as WebP, which keeps its transparency and usually produces a smaller file. Anything else — JPG, WebP — is encoded as JPG. If you want a specific format, choose it in the dropdown rather than leaving it on Auto.
Can I compress a PNG and keep it a PNG?
No, and the reason is technical rather than an oversight. PNG is lossless, so there is no quality setting to expose. To reduce a PNG's weight you have to change its format, which is what the Auto option does by routing it to WebP.
What quality should I pick for photographs?
Start at 75% and compare. The tool's own guidance points at 70–80% for the best balance on photos, and 85–95% if the image has fine detail or smooth gradients that band easily. Below about 50% expect visible blocking.
Does my photo leave the device?
No request is issued — the re-encode happens locally in the browser tab. You can watch for yourself in the Network panel of DevTools while compressing.

Related Guides

View all guides →
Image & PrivacyDo Image Converters Upload Your Photos?A converter that runs inside the page decodes your file into memory and re-encodes it there, so nothing is sent anywhere and you can check that claim yourself in the Network tab. That is a different promise from a server-side tool, where the photo lands on hardware you do not control. What each format costs, and how to verify it, is below; to convert a file now, the PNG to JPG converter linked from this guide works in the browser.