Free Online Developer Tools That Stay Private
Free, fast, and browser-based. Encode, decode, convert, and compare — every operation runs locally. Your data never leaves your device.
Client-side only
No accounts
Always free
Popular Tools
Handpicked, frequently used JSON Formatter & Validator
Format, minify, or validate JSON instantly — free, private, and browser-based.
Password Generator
Generate strong random passwords with customizable length and characters — cryptographically secure and browser-based.
Hex to Decimal Converter
Convert hex to decimal or decimal to hex — instant results, free, and fully browser-based.
Diff Checker
Compare two blocks of text side by side and instantly see the diff — additions, deletions, and modifications highlighted. Also known as text compare.
Converters
View all 13 → JSON to CSV Converter
Paste a JSON array and convert it to CSV — download the result or copy to clipboard. Free and browser-based.
YAML to JSON Converter
Paste YAML and convert it to formatted JSON — free, instant, and fully browser-based.
TOML to JSON Converter
Convert between TOML and JSON formats instantly — bidirectional, with full support for TOML tables and arrays.
XML to JSON Converter
Paste XML and convert it to clean, structured JSON — free, instant, and fully browser-based.
CSV to JSON Converter
Paste CSV data and convert it to a JSON array of objects — free, instant, and fully browser-based.
JSON to YAML Converter
Convert JSON data to YAML format instantly — free, private, and browser-based.
JSON to XML Converter
Convert JSON data to XML format instantly — free, private, and browser-based.
HTML to JSX
Paste HTML and get valid JSX — class becomes className, styles become objects, void elements self-close.
Case Converter
Convert any text between 14 common programming and writing cases — all in one place, all in your browser.
JSON to TypeScript
Paste any JSON and get clean TypeScript interfaces — nested, deduplicated, and configurable.
JSON to C#
Paste JSON and instantly get C# class definitions with typed properties, nested classes, and List<T> arrays.
JSON to Go
Paste JSON and instantly get Go struct definitions with typed fields, json tags, and PascalCase naming.
JSON Schema Generator
Paste any JSON and instantly generate a JSON Schema (Draft 2020-12) with inferred types, required fields, and string format detection.
Formatters
View all 10 → SQL Formatter
Format and beautify SQL queries instantly — supports MySQL, PostgreSQL, SQLite, and more. Free and browser-based.
JSON Formatter & Validator
Format, minify, or validate JSON instantly — free, private, and browser-based.
JavaScript Minifier
Minify and compress JavaScript code instantly — shows size savings. Free, private, and browser-based.
CSS Minifier
Minify and compress CSS code instantly — shows size savings. Free, private, and browser-based.
CSS Beautifier
Paste minified or messy CSS and get cleanly formatted output with proper indentation, spacing, and structure.
HTML Beautifier
Beautify minified HTML with proper indentation and line breaks — free, instant, and browser-based.
XML Formatter
Format and beautify XML with proper indentation — free, instant, and browser-based.
HTML Minifier
Minify and compress HTML code instantly — shows size savings. Free, private, and browser-based.
SVG Optimizer
Paste or upload an SVG and get an optimized version with size savings — powered by SVGO with configurable options.
JSON Comments Stripper
Paste JSON with comments (JSONC) and get clean, strict JSON — removes // line comments, /* block comments */, and trailing commas.
Encoding
View all 9 → Base64 Decode & Encode
Decode or encode any Base64 string instantly — free, private, and runs entirely in your browser.
Base32 Encode & Decode
Encode text to Base32 or decode Base32 strings back to text — instant, bidirectional, RFC 4648 compliant.
JWT Decoder
Paste a JWT to decode and inspect its header, payload, and signature — free, private, nothing leaves your browser.
URL Encode & Decode
Encode or decode URLs instantly — convert special characters to percent-encoding and back. Free and browser-based.
HTML Encode & Decode
Encode special characters to HTML entities or decode them back — free, instant, and browser-based.
JSON Stringify & Escape
Stringify JSON to a single line, escape special characters for embedding in strings, or unescape a JSON-escaped string.
Binary Translator
Translate text to binary code or decode binary back to text — instant bidirectional conversion. Also known as a text-to-binary converter.
Morse Code Translator
Translate text to Morse code or Morse code back to text — free, instant, and browser-based.
Image to Base64
Encode any image to a Base64 data URI — drag and drop, copy as CSS or HTML, 100% browser-based.
Generators
View all 10 → UUID Generator
Generate UUID v4 (random) or v7 (time-based) identifiers — also works as a GUID generator. Free and browser-based.
Hash Generator
Generate cryptographic hashes from any text — SHA-256, SHA-1, SHA-384, SHA-512. Free, private, and browser-based.
Lorem Ipsum Generator
Generate placeholder text in paragraphs, sentences, or words — free, instant, and browser-based.
Password Generator
Generate strong random passwords with customizable length and characters — cryptographically secure and browser-based.
Cron Expression Generator
Build cron expressions visually, see human-readable descriptions and next run times — free and browser-based.
QR Code Generator
Turn any text or URL into a QR code — free, private, download as PNG or SVG.
Bcrypt Generator
Hash passwords with bcrypt or verify a plain-text password against an existing hash — all in your browser.
Slug Generator
Turn any title or phrase into a clean URL slug — handles Unicode, diacritics, and configurable options.
Random Number Generator
Generate random numbers in any range using your browser's crypto API — integers or decimals, with sorting and duplicate control.
Dockerfile Generator
Generate a production-ready Dockerfile from a form with templates for Node.js, Python, Nginx, Go, and Rust — layer-cache-friendly, non-root user, exec-form CMD.
Calculators
View all 8 → Hex to Decimal Converter
Convert hex to decimal or decimal to hex — instant results, free, and fully browser-based.
Epoch & Unix Timestamp Converter
Convert epoch to date or date to epoch timestamp — auto-detects seconds and milliseconds. Free and browser-based.
Binary to Decimal Converter
Convert binary to decimal or decimal to binary — instant results, free, and fully browser-based.
Number Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal — free, instant, and browser-based.
Chmod Calculator
Calculate Unix file permissions interactively — convert between numeric and symbolic notation. Free and browser-based.
IP Subnet Calculator
Calculate subnet mask, network address, broadcast, and host range from any IP and CIDR — free and browser-based.
Color Converter
Convert hex to RGB, RGB to hex, HSL, or HSV — instant bidirectional conversion with live preview. Free color converter, runs in your browser.
Roman Numeral Converter
Convert between numbers and Roman numerals — supports 1 to 3999. Free, instant, and browser-based.
Reference
View all 10 → URL Parser
Paste any URL to break it down into protocol, host, path, query parameters, and fragment — free and browser-based.
JSON Viewer
Paste JSON and explore it as an interactive tree — collapse nodes, search keys, copy paths, and see types at a glance.
Markdown Preview
Write Markdown and convert it to HTML in real time — live preview, syntax highlighting, and copy-to-clipboard. Free and browser-based.
Word & Character Counter
Count words, characters, sentences, paragraphs, and reading time — free, instant, and browser-based.
HTML Viewer
Paste HTML or load an HTML file and see it rendered live in your browser — with tag counts, character stats, and a sanitized source view.
ASCII Table
Browse all 128 ASCII characters with decimal, hex, octal, and binary values — searchable and free.
YAML Validator
Validate YAML syntax and see errors with line numbers — free, instant, and browser-based.
CSV Viewer
Paste CSV data and view it as a formatted, scrollable table — free, instant, and browser-based.
HTTP Status Codes
Searchable reference of every HTTP status code — names, descriptions, and the RFCs that define them.
MIME Type Lookup
Bidirectional reference — find the MIME type for any file extension, or the extensions for any MIME type.
Comparison
View all 3 → Diff Checker
Compare two blocks of text side by side and instantly see the diff — additions, deletions, and modifications highlighted. Also known as text compare.
Regex Tester
Test regex patterns with real-time highlighting, capture groups, and flag controls — free, private, and browser-based.
JSON Compare
Compare two JSON objects side by side and see structural differences — added, removed, and changed keys, with full paths. Free and browser-based.
63 tools and counting.
Frequently Asked Questions
What is CodeBoxTools?
CodeBoxTools is a collection of 63 free, browser-based developer tools. Every tool runs 100% client-side — your data never leaves your device. No accounts, no tracking, no uploads.
Is CodeBoxTools really free?
Yes. Every tool is completely free with no usage limits, no signup, and no premium tiers. The site is supported by clearly labeled affiliate links to developer services.
Is my data safe on CodeBoxTools?
Yes. All processing happens in your browser using JavaScript. Nothing is sent to any server, nothing is logged, and nothing is stored. There are no analytics, no tracking cookies, and no third-party scripts.
What tools does CodeBoxTools offer?
CodeBoxTools offers 63 developer tools across 7 categories: converters (JSON, CSV, YAML, XML), formatters (JSON, SQL, HTML, CSS, JavaScript), encoding (Base64, URL, HTML entities, JWT), generators (UUID, password, QR code, hash), calculators (hex, binary, subnet, chmod, epoch), reference (ASCII table, HTTP status codes, MIME types), and comparison (text diff, JSON diff, regex tester).
Does CodeBoxTools work offline?
CodeBoxTools requires an initial page load from the web, but once a tool page is loaded, most tools work without an active internet connection since all processing is done in your browser.