Developer Tools
16 Free Developer Tools Every Programmer Should Bookmark
Published June 7, 2026 · 6 min read
Every developer keeps a mental list of "quick tools" they reach for throughout the day — a JSON formatter to make an API response readable, a base64 decoder for a config value, a regex tester before pasting into production code. The problem is these tools are scattered across dozens of sites with varying quality, ads and login prompts.
Here are 16 free developer tools on Nutilz, all client-side (nothing is sent to a server), all instantly accessible with no account required.
Data Formatting
JSON Formatter — Paste messy JSON to format, validate and highlight errors. Also supports minification for production use. Error messages point to the exact problem line.
CSV to JSON Converter — Convert CSV to JSON and JSON to CSV with configurable delimiter support. Handles quoted fields and headers automatically.
Markdown Table Generator — Build Markdown tables visually — add rows and columns, fill in values and copy the formatted table syntax ready to paste into a README or PR description.
Encoding & Decoding
Base64 Encoder & Decoder — Encode text or files to Base64 and decode Base64 strings back to plain text. Useful for embedding images in CSS, handling email attachments and reading config values.
URL Encoder & Decoder — Percent-encode strings for use in query parameters or decode encoded URLs. Handles the full RFC 3986 character set.
HTML Entities Encoder — Convert special characters (<, >, &, ") to HTML entities and decode entity strings back to characters.
Text to Binary Converter — Convert text to binary, hexadecimal, decimal and octal representations — and back. Useful when working with low-level data or encoding problems.
Authentication & Security
JWT Decoder — Paste a JSON Web Token to decode and inspect the header, payload and expiry. Runs 100% in the browser — your token is never sent to any server.
Hash Generator — Generate SHA-1, SHA-256 and SHA-512 hashes for any input string. Useful for verifying checksums and generating content hashes.
IDs & Timestamps
UUID Generator — Generate UUID v4 (random) and UUID v7 (time-ordered) identifiers. Supports bulk generation and copy-on-click. UUID v7 is recommended for database primary keys to avoid B-tree index fragmentation.
Timestamp Converter — Convert Unix timestamps to human-readable dates and convert dates back to Unix timestamps in seconds or milliseconds.
Testing & Debugging
Regex Tester — Write a regex pattern and test it against a string with live match highlighting. Supports flags (global, case-insensitive, multiline) and shows captured groups.
Cron Expression Parser — Paste a cron expression to get a plain-English description and a preview of the next scheduled run times. Supports standard 5-field and 6-field (with seconds) expressions.
HTTP Status Codes Reference — A searchable reference for all HTTP status codes from 100 to 599, with descriptions and common use cases for each.
URLs & Numbers
URL Parser — Decompose any URL into its protocol, host, port, pathname, query parameters and hash fragment. Useful for debugging webhook URLs and API endpoints.
Base Converter — Convert numbers between binary (base 2), octal (base 8), decimal (base 10) and hexadecimal (base 16).
All in One Place
All 16 developer tools are free, run entirely in the browser and require no sign-up or extension. Visit the Developer Tools hub to browse the full list, or search from the Nutilz homepage.