Every image tool website wants you to upload your photos to their server. I never liked that — especially when the photos are personal.
So I built 5 image tools that process everything in your browser. The image data stays in JavaScript memory, gets processed by Canvas API or WebAssembly, and the result is downloaded directly.
How Client-Side Image Processing Works
Modern browsers have incredible built-in capabilities:
- Canvas API — Draw, transform, and export images at pixel level. Resize, crop, compress, all without plugins.
- WebAssembly — Run compiled C/C++ code at near-native speed. This is how the background remover runs a full AI model.
- EyeDropper API — Pick any color from your screen without taking a screenshot.
With these three APIs, you can build professional-grade image tools that never need a server.
The 5 Tools
1. Image Compressor
Drag in a JPG, PNG, or WebP. Adjust quality slider. Download the compressed version.
How it works: Canvas API re-encodes the image at your chosen quality level. For PNG, it also strips metadata. For JPEG, it uses the browser's native JPEG encoder.
Free limit: 5 MB per image. PRO: unlimited size.
2. Image Resizer
Resize by percentage, pixels, or max dimension. Aspect ratio lock. Preview before downloading.
How it works: Canvas API draws the image at the target dimensions using drawImage(). Bilinear interpolation by default, high-quality if browser supports it.
Free: 5 MB. PRO: unlimited.
3. Image Cropper
Interactive crop selector on the image. Touch-friendly for mobile. Set aspect ratios (1:1, 4:3, 16:9, freeform).
How it works: Canvas drawImage() with source rectangle coordinates extracts the cropped region.
Free: 5 MB. PRO: unlimited.
4. AI Background Remover
This is the most technically interesting one. It runs a neural network (ISNet) entirely in-browser via ONNX Runtime Web with WebAssembly backend.
How it works:
- The ONNX model (~40 MB) downloads on first use and caches in browser storage
- Your image is preprocessed to 1024x1024
- The model runs inference in WebAssembly — ~5 seconds per image
- The alpha mask is applied to create a transparent PNG
No API key. No cloud credits. No server processing. Just your browser and a neural network.
Free: 720p output. PRO: full HD+, batch processing, background color replacement.
5. Color Picker
Click a color on the color wheel, paste a hex code, or use the EyeDropper API to pick directly from your screen. Converts between HEX, RGB, and HSL in real-time.
Also saves color history to localStorage.
Performance Comparison
| Tool | Free Limit | Processing Time | Output Quality |
|---|---|---|---|
| Image Compressor | 5 MB | ~1s | Configurable |
| Image Resizer | 5 MB | < 1s | Bilinear |
| Image Cropper | 5 MB | < 1s | Lossless crop |
| Background Remover | 720p | ~5s per image | AI neural network |
| Color Picker | Unlimited | Real-time | N/A |
Privacy First
These tools are genuinely private — not "privacy policy" private, but technically private:
- No server receives your files (there is no server)
- No analytics script tracks your usage
- No cookies (except color history you choose to save)
- Works offline after first load
- View source to verify — it's just HTML and JS
One Key, All Tools
All 5 image tools are part of a 24-tool collection. The free versions have generous limits. A single PRO key ($19.99, one-time) removes all limits across every tool. No subscription.
Source code for everything is on GitHub — MIT license.
Previously: 7 Free PDF Tools That Never Upload Your Files