Image

Image Compressor

Shrink an image's file size with an adjustable quality slider, and see exactly how much you saved before downloading.

Click to upload or drag and drop a JPG, PNG or WebP image here

Quality: 80%

How to use the image compressor

Upload or drag in a JPG, PNG or WebP image.
Adjust the quality slider and compare the before/after previews and sizes.
Download the compressed image.

Features

Drag-and-drop or click-to-upload
Live before/after size and percentage saved
Adjustable quality from 10% to 95%
Image never leaves your browser — compression happens on your device using the Canvas API

Need an exact KB limit?

The quality-slider compressor is best when you simply want a smaller file. If an upload form requires a maximum size, use the Photo Size Compressor or a preset for 20KB, 50KB, 100KB, 200KB or 500KB.

Balance image quality and file size

Image compression is a trade-off: stronger compression usually creates a smaller file but can soften detail or introduce visible artifacts. Photos often tolerate more compression than screenshots, diagrams or images containing small text.

For websites, start with the smallest size that still looks clean at the display dimensions you actually need. If an upload form has a strict KB limit, use one of ToolNova’s exact-size compressors after choosing sensible image dimensions.

Frequently asked questions

No. The image is decoded and re-compressed locally in your browser using the HTML5 Canvas API; it's never sent anywhere.

PNG compression is lossless, so to actually shrink file size at adjustable quality we re-encode as JPG once you lower the quality slider below 95%. If you need to keep transparency, use a quality of 95% or the PNG-specific settings on the Image Resizer instead.

Related tools

Image Resizer

Resize an image to exact pixel dimensions, with optional locked aspect ratio.

JPG to PNG Converter

Convert a JPG or JPEG photo into a PNG file.

PNG to JPG Converter

Convert a PNG into a JPG, with a background colour for transparent areas.

Image to PDF

Combine one or more images into a single downloadable PDF.

Choosing the right compression goal

There is no single “best” quality percentage. A photo, screenshot and scanned document fail in different ways when compressed, so judge the result by the details that matter for its destination rather than by file size alone.

For photos, inspect faces and textured areas for blockiness.
For screenshots, check small text and sharp UI edges.
If a website gives a hard KB limit, use the target-size compressor instead of guessing quality.