How accurate is the target file size?

The tool uses binary search with up to 20 iterations to find the JPEG quality that produces a file size within 1% of your target. In most cases, the result is within a few KB of the target.

What image formats are supported?

You can upload JPG, PNG, and WebP images. The compressed output is always in JPEG format since JPEG allows quality-based compression for precise file size control.

Why is the output always JPEG?

JPEG compression allows fine-grained quality control (1-100%), making it possible to target a specific file size. PNG uses lossless compression and does not support quality-based size targeting.

What if my target size is too small?

If the target is very small (e.g., 5 KB for a large image), the tool will compress to the lowest possible quality. The result may be visually degraded but will be as close to the target as possible.

Are my images uploaded to a server?

No. All compression happens in your browser using the Canvas API. Your images never leave your device, ensuring complete privacy.

Compress Image to KB

Compress any image to an exact target file size in KB — 50 KB, 100 KB, 200 KB, or any custom size.

Updated Mar 2026100% Private — runs in browser

Drag & drop your image here or browse

JPG, PNG, WebP — max 25 MB

How Compress Image to Exact KB Works

This tool lets you compress any image to an exact target file size in KB. Whether you need to compress an image to 50 KB, 100 KB, or 200 KB for form uploads, email attachments, or website requirements, this tool finds the precise JPEG quality setting to match your target.

How it works: The tool uses a binary search algorithm on the JPEG quality parameter (ranging from 1% to 100%). It draws your image on an HTML5 Canvas and repeatedly exports it with different quality values, narrowing down in up to 20 iterations to find the quality that produces a file size closest to your target KB.

Privacy: All processing happens entirely in your browser. Your images are never uploaded to any server.

How to Use Compress Image to KB

1
Upload an image by dragging and dropping or clicking the upload area.
2
Enter your desired target file size in KB (e.g., 50, 100, 200).
3
Click "Compress" to start the binary search compression.
4
View the result: compressed size, quality used, reduction percentage, and iterations.
5
Download the compressed image with one click.

About Compress Image to KB

Compress any image to an exact target file size in KB with our free online tool. Need exactly 50 KB, 100 KB, or 200 KB for a form, application, or email? Our smart binary search algorithm finds the perfect JPEG quality setting for your target.

Key Features

Binary Search Compression: Iterates up to 20 quality levels to find the closest match to your target KB.
Custom Target Size: Enter any KB value — 50 KB, 100 KB, 200 KB, or any custom size.
Detailed Results: Shows resulting file size, JPEG quality used, compression percentage, and iteration count.
Multiple Input Formats: Accepts JPG, PNG, and WebP images.
Instant Download: Download the compressed image with one click.

Who Is This For?

Perfect for government form uploads, job applications, passport photo submissions, and any scenario where an exact file size limit is enforced.

Privacy & Security

All processing happens in your browser using HTML5 Canvas — your images are never uploaded to any server. No watermarks, no signup, no limits.