⚙️ Free Developer Tools
The small utilities you reach for a dozen times a week. All of them run locally in the browser — your JSON, your tokens, and your passwords never leave the machine you are sitting at.
Split a File
Break a large file into numbered pieces small enough to email or upload — and joinable again without any tool.
Join Split Files
Reassemble .001 and .part pieces into the original file, with the order detected and missing pieces flagged.
Random File Generator
Generate a dummy file of an exact size, random bytes or zeros, for testing upload limits and storage.
JSON Formatter & Validator
Format, minify, and validate JSON online with instant error messages and quick stats.
RSS & Atom Feed Parser
See every item in an RSS or Atom feed and catch missing images, bad dates and relative links.
Base64 & URL Encoder/Decoder
Encode and decode text as Base64 or URL-safe strings, with full UTF-8 support.
Text Diff Checker
Compare two texts and see exactly what was added, removed, or changed, line by line.
Case Converter
Convert text between UPPERCASE, Title Case, camelCase, snake_case, kebab-case and more.
Color Contrast Checker
Check text and background colors against WCAG AA/AAA accessibility standards.
Password Generator & Strength Checker
Generate cryptographically secure passwords and check the strength of an existing one.
Can My Computer Run This AI Model?
Check whether a local AI model fits in your graphics card or system memory, from its size and quantization.
GPU Temperature & Hotspot Checker
Is the gap between your GPU temperature and hotspot normal? A verdict based on published Nvidia and AMD limits.
Merge PDF Files
Combine several PDF files into one, in the order you choose. Runs in your browser; nothing is uploaded.
Split PDF
Save a range of pages as a new PDF, or split every page into its own file. Nothing is uploaded.
Upload & Download Time Calculator
How long a file takes to upload or download at your connection speed, with a realistic efficiency setting.
PC Power Cost Calculator
Energy use and running cost of a computer per month and year, from its wattage and your electricity price.
Storage Space Calculator
How many photos, videos or songs fit on a drive or card, and why 1 TB shows as 931 GB in Windows.
Quantum Speed-up Calculator
How the state space grows with each qubit, and how many steps Grover’s search needs versus an ordinary computer.
How to get the most out of these
These are deliberately small: each does one thing you would otherwise script, search for, or do badly by hand. The JSON formatter validates with the browser's own parser, the password generator uses the cryptographic randomness your password manager uses, and the diff runs the same algorithm family as Git. Nothing here is a toy version of the real thing - for these narrow jobs, this is the real thing.
Local execution matters most in this category, because the things developers paste are the things that must not leak: API responses full of customer data, tokens, connection strings, passwords. Every tool on this page works offline once loaded. If you are ever unsure, open the network tab and watch - nothing leaves.
The limits are the flip side of the smallness: no JSON repair, no diff for binary files, no password vault. When a job outgrows the tool, the tool's own page says so and points at what to use instead.