🖼️ Free Image Compressor
Image Compressor Online – Compress to 9KB, 10KB, 20KB or Any Size
The only free tool that can compress JPG, PNG, and WebP images to any target size — even 9KB or below. Uses a smart dual-pass algorithm (quality reduction + smart rescaling) to hit your exact size target. 100% browser-based. Your images never leave your device.
🖼️ Image Compressor & Converter
Upload an image, choose your target size and format, and get an optimised file instantly.
Drag & Drop your image here
or click to browse — JPG, PNG, WebP, GIF, BMP supported
💡 Tip: You can also paste an image with Ctrl+V / Cmd+V
💡 Best quality tip: Choose JPG + Auto mode for the best quality at any target size. Use Smart Resize only if you need to reach very small targets like 9–10 KB.
Allow smart dimension scaling if needed
When ON: tool may reduce image dimensions to meet tiny targets (e.g. 9KB). When OFF: only quality is reduced.
Analysing image…
Original Size
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Compressed Size
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Size Reduced
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Dimensions
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Visual Quality Level
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Before
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After
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How It Works
1
Upload Image
Drag & drop, click to browse, or paste with Ctrl+V
2
Set Target Size
Choose a preset (even 9KB!) or enter any custom KB value
3
Compress
Smart dual-pass algorithm reduces quality + dimensions to hit target
4
Download
Preview before & after, then download your optimised file
100% Private
All compression happens in your browser. Your images are never uploaded to any server.
Hits Any Target
Dual-pass algorithm: first reduces JPEG quality, then scales dimensions — can reach 9KB and below.
3 Output Formats
Convert to JPG (smallest), WebP (modern browsers), or PNG (lossless). Mix and match freely.
Works Everywhere
Fully responsive. Works on iPhone, Android, tablet, and desktop — no app install needed.
Why This Tool Outperforms Every Other Image Compressor Online
Most image compressors online only reduce JPEG quality. When you set a target of 10KB, they just keep lowering quality until they're as close as they can get — but if the image is very large (e.g. a 5MB photo), they hit their quality floor and give up, often returning a 40KB file when you asked for 10KB.
Our tool uses a dual-pass smart algorithm:
- Pass 1 – Quality Reduction: Iteratively lowers JPEG/WebP quality from 92% down to a minimum threshold to reach the target size.
- Pass 2 – Smart Dimension Scaling: If quality reduction alone isn't enough, the tool intelligently reduces pixel dimensions (width/height) while preserving aspect ratio, then repeats the quality pass.
This two-stage approach is why we can achieve targets as low as 9KB — a threshold no other commonly available free tool reliably hits. 9KB files are useful for government portal uploads, email attachments with strict size limits, WhatsApp DP quality optimisation, and low-bandwidth web use.
Feature Comparison
| Feature | WhizbangTools ✅ | Typical Competitors |
|---|---|---|
| Target as low as 9KB | ✅ Yes | ❌ Rarely below 15–20KB |
| Dual-pass (quality + resize) | ✅ Yes | ❌ Quality-only |
| Before / After preview | ✅ Yes | ❌ Often missing |
| Visual quality indicator | ✅ Yes | ❌ No |
| Custom KB target | ✅ Yes | Partial |
| No server upload (privacy) | ✅ 100% browser | ❌ Most upload to server |
| JPG, WebP, PNG output | ✅ All 3 | Partial |
| Paste from clipboard | ✅ Yes | ❌ Rarely |
| Free, no sign-up | ✅ Always free | Partial |
Frequently Asked Questions
Can this tool really compress an image to 9KB?
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Yes — this is the key feature that sets our tool apart. Most image compressors only reduce JPEG quality, which has a floor around 15–25KB for typical photos. Our tool uses a dual-pass algorithm: first it reduces quality, then it intelligently scales down image dimensions until the file meets your target. This means even 9KB targets are achievable. The resulting image will be smaller in pixel dimensions, but the file size will accurately match your requirement — perfect for government form uploads, email systems, and low-bandwidth environments.
Is my image uploaded to your server?
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No. This tool is 100% client-side. All compression happens inside your web browser using the HTML5 Canvas API. Your image data never leaves your device and is never transmitted to our servers or any third party. This makes it completely safe for compressing sensitive photos such as ID documents, medical images, or personal photographs.
Which format should I choose — JPG, WebP, or PNG?
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Choose JPG for the smallest file sizes — it's ideal for photographs and when hitting very low KB targets (under 20KB). Choose WebP if you're optimising images for a website; it produces 25–35% smaller files than JPG at the same visual quality and is supported by all modern browsers. Choose PNG only if you need a transparent background or pixel-perfect lossless quality — PNG files will be significantly larger than JPG or WebP at any given target size.
What does "Smart Resize" mode do differently?
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In Smart Resize mode, if reducing JPEG quality alone cannot meet your target size, the tool will progressively scale down the image pixel dimensions (width and height), always preserving the original aspect ratio, until the compressed file falls within your target. This is especially important for very low targets like 9KB or 10KB where a high-resolution photo cannot physically be compressed small enough by quality reduction alone.
Why does the compressed file sometimes not hit the exact target size?
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JPEG and WebP compression are not perfectly predictable — the actual output size depends on image complexity (a solid-colour image compresses far more than a detailed photograph). Our algorithm always aims to get the file size at or below your target. If it cannot reach the target even at minimum quality and smallest dimensions, it will return the closest possible result and display a warning. For PNG format, true lossless compression means very small targets may not be reachable without reducing dimensions.
Is this tool free to use?
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Yes, completely free. No sign-up, no account, no watermarks, no daily limits. You can compress as many images as you need. WhizbangTools provides this tool at no cost as part of its free suite of online tools for engineers, students, and creators.
Can I convert a PNG to JPG using this tool?
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Yes. Upload any supported image (JPG, PNG, WebP, GIF, BMP) and select JPG, WebP, or PNG as the output format. The tool will convert and compress simultaneously. This is useful when you receive a large PNG and need a small JPG — for example for passport photo uploads, online application forms, or email attachments.
Does it work on mobile phones?
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Yes. This tool is fully responsive and works on all modern smartphones and tablets — Android and iOS. You can pick images from your phone's gallery or camera roll, compress them, and download the result directly to your device. No app installation required.