Image Tool

Free Image Compressor - Reduce Image File Size Online

Compress your images directly in your browser. No uploads to any server - your photos stay completely private. Reduce JPEG, PNG, and WebP file sizes with full quality control.

100% Private - No Server UploadsInstant ResultsFree Download

Compress Images

Drag and drop images here

or click to browse. Supports JPEG, PNG, WebP.

How to Use This Tool

Upload Your Images

Drag and drop images onto the upload area or click to browse your files. You can upload JPEG, PNG, and WebP images. Multiple files are supported for batch compression.

Choose Settings

Select a compression mode: Quality (set exact %), Target Size (set a file size limit), or Smart (auto-optimize). Pick an output format to convert between JPEG, WebP, or PNG.

Compress and Download

Click Compress All to process your images. Compare the before and after with the interactive slider. Download individual files or all at once when you are satisfied.

How Image Compression Works

canvas.toBlob(mimeType, quality)

This tool uses the browser's built-in Canvas API to compress images entirely on your device. The process is simple and effective:

Load: Your image is read into an HTML <canvas> element using the FileReader API
Encode: The canvas re-encodes the image in your chosen format (JPEG, WebP, or PNG) with the specified quality level
Optimize: For lossy formats (JPEG, WebP), the quality parameter controls how much data is discarded. Lower quality = smaller file, with diminishing visual loss above 60%

Lossy compression (JPEG, WebP) works by removing visual information the human eye is less sensitive to, such as subtle color gradients and high-frequency detail. At 80% quality, most images are visually indistinguishable from the original while being significantly smaller.

Lossless compression (PNG) does not discard data. Instead, the canvas re-encoding strips metadata and can sometimes achieve modest size reductions through better internal encoding.

Frequently Asked Questions

Are my images uploaded to a server?

No. This image compressor works entirely in your browser using the Canvas API. Your images never leave your device. There are no server uploads, no data collection, and no privacy concerns. Everything happens locally on your machine.

What image formats are supported?

You can compress JPEG, PNG, and WebP images. You can also convert between formats - for example, convert a PNG to JPEG for smaller file sizes. The output format selector lets you choose between keeping the original format or converting to JPEG, WebP, or PNG.

What is the difference between lossy and lossless compression?

Lossy compression (JPEG, WebP) reduces file size by discarding some image data that is less perceptible to the human eye. You control how much data is removed via the quality slider. Lossless compression (PNG) reduces file size without losing any image data, typically by optimizing how the data is stored. Lossy compression generally achieves much smaller file sizes.

What does the quality slider do?

The quality slider controls how much compression is applied. At 100%, very little data is discarded and the image looks nearly identical to the original. At lower values like 60% or below, more data is removed, resulting in smaller files but potentially visible artifacts. For most purposes, 70-85% quality provides an excellent balance of size and visual quality.

How does target size mode work?

Target size mode lets you specify the exact file size you want (e.g., 200 KB). The tool automatically adjusts the compression quality using a binary search algorithm to get as close to your target size as possible, within approximately 5% accuracy. This is useful when you need to meet specific file size limits for uploads.

Can I compress multiple images at once?

Yes. You can upload multiple images by dragging and dropping them or selecting multiple files from the file picker. All images will be compressed with the same settings. You can then download each individually or download all compressed files at once.

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