All Tools
Every tool on Build Stack — 70 in total — organized by category. Search to filter instantly, or expand a category to browse.
Formatters & Converters
13 toolsJSON Formatter
Format, validate and minify JSON with syntax highlighting.
JSON ↔ YAML
Convert between JSON and YAML instantly — two-way.
JSON ↔ CSV
Convert JSON arrays to CSV and CSV back to JSON.
JSON Escape / Unescape
Escape special characters for JSON strings and unescape them back.
JSON Schema Generator
Paste JSON and auto-generate a JSON Schema (Draft 2020-12).
XML Formatter
Format, validate and minify XML documents.
HTML Formatter
Prettify and minify HTML markup.
SQL Formatter
Format SQL queries for MySQL, PostgreSQL, SQLite, T-SQL and BigQuery.
Base64 Encode / Decode
Encode text or files to Base64 and decode Base64 strings.
URL Encode / Decode
Encode and decode URL components and full URLs.
HTML Entities
Encode and decode HTML entities with a reference table.
TOML ↔ JSON
Convert between TOML and JSON formats — two-way.
JSON Diff Checker
Compare two JSON values and see a structured, semantic difference report.
Generators
14 toolsUUID / ULID Generator
Generate UUID v1–v7 and ULID identifiers in bulk.
Password Generator
Generate strong, secure passwords with custom rules and strength meter.
Lorem Ipsum Generator
Generate Lorem Ipsum words, sentences, paragraphs or JSON arrays.
Random Data Generator
Generate fake names, emails, addresses, UUIDs and more as JSON or CSV.
Mock JSON Generator
Define a schema and generate realistic mock JSON data.
QR Code Generator
Generate QR codes for URLs, text and more — customise colors and download.
Favicon Generator
Upload an image or enter text/initials to generate favicons in all sizes.
Cron Expression Parser
Parse cron expressions into plain English and preview next run times.
.env Validator
Validate .env files for syntax errors, weak secrets and missing values.
.gitignore Generator
Generate .gitignore files for Node, Python, Java, Go, Rust and more.
Meta Tags & OG Generator
Generate SEO meta tags and Open Graph / Twitter Card markup with a live preview.
robots.txt Generator
Build a robots.txt file with per-bot rules, sitemap and crawl-delay.
.htaccess Generator
Generate .htaccess rules for HTTPS redirects, www handling, caching and more.
Placeholder Image Generator
Generate placeholder images as SVG data URLs with custom size, colors and text.
Security & Crypto
9 toolsTOTP / 2FA Generator
Generate live TOTP (RFC 6238) codes from a Base32 secret — the algorithm behind Google Authenticator.
JWT Decoder
Decode and inspect JSON Web Tokens — header, payload, signature.
JWT Builder
Build and sign JWT tokens with custom claims and HMAC secrets.
Hash Generator
Generate MD5, SHA-1, SHA-256, SHA-512 hashes from text.
bcrypt Generator
Hash passwords with bcrypt and verify hashes — configurable salt rounds.
AES Encrypt / Decrypt
Encrypt and decrypt text with AES, DES, TripleDES and more — browser-only.
CSP Header Generator
Build a Content-Security-Policy header by configuring each directive.
File Checksum Verifier
Compute and verify SHA-1, SHA-256, SHA-384 and SHA-512 hashes of any file.
RSA Key Pair Generator
Generate RSA public/private key pairs (PEM format) entirely in your browser.
Network & Web
5 toolsRegex Workbench
Test regular expressions with live match highlighting, group capture, and a library of common patterns like email, URL, phone and more.
Time Zone Converter
Convert times across multiple time zones with a live world clock.
cURL → Code Converter
Convert cURL commands to JavaScript, Python, Go, PHP, Ruby, Java, C#, Swift, C++, Rust and more.
User-Agent Parser
Parse a User-Agent string into browser, engine, OS and device details.
Subnet / CIDR Calculator
Calculate network address, broadcast, netmask and host ranges from CIDR.
Text & Strings
8 toolsSlug Generator
Convert any title or phrase into a URL-safe slug, snake_case or dot.case.
String Case Converter
Convert strings between camelCase, snake_case, kebab-case, PascalCase and more.
Text Diff Checker
Compare two texts side-by-side with char, word and line-level diff.
Word Counter
Count words, characters, sentences and get reading time and top words.
Markdown Previewer
Live Markdown preview with GFM support, tables, code blocks and HTML output.
Line Tools
Sort, deduplicate, reverse, shuffle, trim and number lines of text.
Emoji Search & Picker
Search emoji by name or keyword and copy them with one click.
Text Encoding Converter
View text as UTF-8, UTF-16, ASCII or Latin-1 bytes in hex, binary or decimal.
Numbers & Math
9 toolsUnix Timestamp Converter
Convert Unix timestamps to human-readable dates and vice versa.
chmod Calculator
Calculate Unix file permissions visually — numeric and symbolic modes.
Number Base Converter
Convert between binary, octal, decimal and hexadecimal with bit display.
Bitwise Calculator
Perform AND, OR, XOR, NOT, left shift and right shift operations.
Data Size Converter
Convert between bits, bytes, KB, MB, GB, TB and their binary (KiB, MiB) equivalents.
Unit Converter
Convert length, weight, temperature, data size and speed units.
Roman Numeral Converter
Convert numbers to Roman numerals and back.
Date Difference Calculator
Calculate the exact difference between two dates in days, weeks, months and years.
Percentage Calculator
Calculate percentages, percentage of a value, and percentage change.
Design & CSS
7 toolsColor Converter
Convert between HEX, RGB, HSL, HSV, and nearest Tailwind color class.
CSS Gradient Generator
Build linear, radial and conic CSS gradients visually with multi-stop support.
Box Shadow Generator
Build CSS box shadows visually with layered shadow support.
Contrast Checker
Check WCAG color contrast ratios for accessible text and backgrounds.
Flexbox Generator
Visually build and preview CSS flexbox layouts, then copy the code.
CSS @keyframes Generator
Build CSS animations visually with multiple keyframe steps and a live preview.
Border Radius Generator
Visually design CSS border-radius shapes and blobs with live preview.
Reference & Lookups
5 toolsHTTP Status Codes
Complete reference of all HTTP status codes — searchable with descriptions.
MIME Types Reference
Searchable lookup of file extensions and their MIME / content types.
Common Ports Reference
Searchable list of well-known network ports and the services that use them.
CIDR & Subnet Reference
Searchable reference of CIDR prefixes, subnet masks, host counts and private IP ranges.
HTTP Headers Reference
Searchable reference of common HTTP request and response headers and what they do.