JPG and PNG Converter
Load a local image, remove a simple background with traditional color-distance matting, refine alpha with mouse or touch, then export PNG or JPEG.
UsefulTool
Portable browser tools for private, local work. Open a page, use the tool, inspect the source, or keep the repository for offline use.
Tools
Tools run locally in the browser. Advanced pages use audited libraries stored in this repository, never runtime CDNs.
Scientific Calculator
Calculate common functions, trigonometry, powers, constants, and definite integrals locally with a parser that avoids dynamic code execution.
Unit Converter
Convert 18 measurement categories, including scientific, imperial, mechanical, time, angle, frequency, torque, density, acceleration, and digital-rate units.
Image and Video Metadata
Decode EXIF/GPS, XMP, ICC, IPTC, text chunks, and major image/video containers locally, with explicit privacy and secret-like field warnings.
Base64 Converter
Encode text or files, decode standard, URL-safe, and Data URI Base64, inspect bytes, and save binary output.
Side-by-Side File Diff
Compare two text files line by line with aligned additions and removals powered by the vendored jsdiff implementation.
ROT Cipher
Apply Caesar rotations, ROT13, ROT47, inspect every shift, or generate a random password before reversible transformation.
LAN Chat
Exchange manual WebRTC signaling text, then send messages and images directly between LAN peers without a room server.
Layered Image Editor
Load multiple images as interactive layers, move, resize, rotate, reorder, and export with configurable JPEG or WebP quality.
PDF Merge
Arrange local PDFs, select page ranges, and create one merged PDF using the vendored pdf-lib engine.
Images to PDF
Order image files, configure page sizing, margins, captions, and compression, then create a multi-page PDF.
Runtime pages declare `connect-src 'none'` and also disable common network functions in JavaScript. Images and expressions stay inside your browser process.