Developer Tools
75 free tools — no signup required.
The Developer Tools category brings together formatters, converters, generators, and validators that handle the small jobs that interrupt a coding session. Use the JSON Formatter to tidy and validate API payloads, the Regex Tester to check a pattern against sample text, or the Base64 Encoder/Decoder to inspect tokens and data URLs. The set also covers UUID and JWT handling, query builders for SQL and MongoDB, config generators for Docker and Nginx, hashing, and SEO helpers like sitemap and schema markup. Each tool runs in the browser, so code, secrets, and payloads stay on your machine while you format, convert, or generate exactly what you need.
Featured Developer Tools
JSON Formatter
Pretty-print, validate, and minify JSON with a clear error line and column.
Regex Tester
Test JavaScript regular expressions with live match results, capture groups, and flags.
Base64 Encoder/Decoder
Encode or decode Base64 text safely with UTF-8 and an optional URL-safe variant.
UUID Generator
Generate cryptographically random UUID v4 or time-ordered UUID v7 in bulk, in your browser.
JWT Decoder
Decode a JSON Web Token to inspect its header, payload, and expiry — without sending it anywhere.
SQL Formatter
Format SQL queries with clause-level line breaks, indent control, and keyword case.
URL Encoder/Decoder
Percent-encode or decode URLs with a clear choice between full URL and component scope.
Cron Expression Parser
Translate a cron expression to plain English and preview the next five run times.
Formatters & Converters
JSON Formatter
Pretty-print, validate, and minify JSON with a clear error line and column.
XML Formatter
Pretty-print, validate, and minify XML with full attribute and CDATA preservation.
HTML Formatter
Pretty-print or minify HTML with safe handling of script, style, and pre blocks.
SQL Formatter
Format SQL queries with clause-level line breaks, indent control, and keyword case.
Code Formatter
Re-indent brace-based source (JS, TS, Java, C#, Go, Rust, PHP) using a token-aware rewriter.
YAML to JSON Converter
Convert YAML to JSON or JSON to YAML in your browser with one click.
JSON to CSV Converter
Flatten a JSON array of objects into CSV with delimiter and header controls.
CSV to JSON Converter
Parse CSV (or TSV / pipe) into JSON with header detection and optional type inference.
XML to JSON Converter
Convert XML to JSON with @-prefixed attributes and array grouping for repeated elements.
HTML to Markdown Converter
Translate HTML to CommonMark-flavoured Markdown with headings, lists, links, and images.
Markdown to HTML Converter
Render CommonMark Markdown to clean HTML with both source view and a live preview.
Binary Hex Decimal Converter
Convert between binary, octal, decimal, and hexadecimal with BigInt precision.
JavaScript Minifier
Strip comments and collapse whitespace from JS with safe handling of strings, templates, and regex.
CSS Minifier
Shrink CSS by removing comments, collapsing whitespace, and shortening hex colours.
Syntax Highlighter
Token-based code highlighting for JS, TS, Python, JSON, CSS, HTML, and SQL — no remote CDN.
API Response Formatter
Pretty-print, minify, or sort the keys of a JSON API response, with byte counts and error location.
Generators & Config
UUID Generator
Generate cryptographically random UUID v4 or time-ordered UUID v7 in bulk, in your browser.
Git Command Generator
Build the right git invocation for everyday tasks — commit, push, rebase, stash, cherry-pick.
Gitignore Generator
Build a .gitignore from language and tool presets — Node, Python, Go, Terraform, VS Code, macOS, and more.
Docker Compose Generator
Generate a valid docker-compose.yml from per-service inputs — image, ports, env, volumes, depends_on.
Dockerfile Linter
Lint a Dockerfile in your browser for unpinned base images, missing apt cleanup, shell-form CMD, and more.
Kubernetes YAML Generator
Generate Deployment, Service, ConfigMap, Secret, and Ingress manifests with the current stable apiVersion.
Nginx Config Generator
Generate an Nginx server block for static sites or reverse proxy with SSL, HSTS, gzip, and security headers.
Apache .htaccess Generator
Generate a .htaccess file with HTTPS redirect, www handling, gzip, caching, security headers, and custom 301s.
Terraform Snippet Generator
Generate idiomatic Terraform HCL snippets for AWS, Azure, and GCP resources with current provider versions.
Ansible Playbook Generator
Build an Ansible playbook task by task with FQCN modules — apt, service, copy, template, user, git, and more.
CI/CD Pipeline Generator
Generate GitHub Actions, GitLab CI, or CircleCI YAML for Node, Python, Go, Rust, or Java projects.
CDN Configuration Generator
Generate cache and edge configuration for Cloudflare, AWS CloudFront, Fastly, or as portable HTTP headers.
.env File Generator
Build a valid .env file with shell-safe quoting and a matching .env.example with masked values to commit.
.env File Validator
Validate a .env file for duplicate keys, mismatched quotes, unquoted spaces, weak secrets, and bad export.
CORS Header Generator
Generate CORS configuration for Nginx, Apache, Express, Fastify, Flask, Go, or raw HTTP headers.
API Documentation Generator
Generate clean Markdown docs for an HTTP endpoint from form fields — headers, params, request and response examples.
Query Builders
MySQL Query Generator
Build syntactically correct MySQL SELECT, INSERT, UPDATE, and DELETE statements from form fields.
PostgreSQL Query Generator
Build PostgreSQL SELECT, INSERT, UPDATE, and DELETE queries with inline literals or numbered $1/$2 parameters.
MongoDB Query Builder
Build MongoDB shell commands — find, insertOne, updateMany, deleteMany — from JSON filter and document fields.
Redis Command Generator
Build valid redis-cli commands — GET, SET, HSET, LPUSH, EXPIRE, ZADD and more — with safe quoting.
GraphQL Query Builder
Build a valid GraphQL document — query, mutation, or subscription — with arguments and nested selection sets.
Elasticsearch Query Builder
Build Elasticsearch DSL queries — match, term, range, and bool — and emit the full search request body.
Security & Encoding
Base64 Encoder/Decoder
Encode or decode Base64 text safely with UTF-8 and an optional URL-safe variant.
URL Encoder/Decoder
Percent-encode or decode URLs with a clear choice between full URL and component scope.
MD5 Hash Generator
Generate a 32-character MD5 hash from any text, fully client-side.
SHA-256 Hash Generator
Generate a 64-character SHA-256 hash from any text using your browser's native crypto.
Hash Generator
SHA-1, SHA-256, SHA-384, and SHA-512 digests computed via the Web Crypto API.
Bcrypt Generator
Hash plain text with bcrypt or verify a password against an existing bcrypt hash, entirely in your browser.
JWT Decoder
Decode a JSON Web Token to inspect its header, payload, and expiry — without sending it anywhere.
JWT Generator
Sign HS256, HS384, or HS512 JSON Web Tokens with a secret using the Web Crypto API.
htpasswd Generator
Generate a SHA-1 .htpasswd line in your browser — no server, no logs.
HTML Entity Encoder/Decoder
Encode or decode HTML entities — minimal, all non-ASCII, named, and numeric references.
Chmod Calculator
Convert between octal modes, ls -l symbolic form, and a ready-to-paste chmod command.
AWS IAM Policy Generator
Build an AWS IAM policy JSON statement by statement, with action presets, ARN resources, and condition blocks.
OAuth Token Request Generator
Build a ready-to-run cURL command and raw HTTP request for OAuth 2.0 token flows, plus PKCE authorize URLs.
Text & SEO
Regex Tester
Test JavaScript regular expressions with live match results, capture groups, and flags.
Regular Expression Explainer
Plain-English breakdown of any JavaScript regex, with optional sample-text matching.
Case Converter
Convert text between UPPER, lower, Title, camelCase, snake_case, kebab-case, and more.
Capitalize Converter
Capitalize the first letter of every word, sentence, or full AP/APA title.
Text Formatter
Clean up messy text: trim lines, collapse spaces, normalize line endings, and remove blank lines.
Slug Generator
Turn any title into a clean, SEO-friendly URL slug with custom separator and length.
Diff Checker
Side-by-side line diff with add/remove highlighting and a copyable unified diff.
Text Comparison Tool
Compare two texts by character, word, and line counts plus Jaccard similarity.
Palindrome Checker
Check whether a word or sentence reads the same forwards and backwards, with per-word scan.
Title Tag Generator
Generate an SEO-friendly <title> tag with live character and pixel-width counters against the 580px SERP budget.
Meta Description Generator
Generate a meta description tag with live character count and focus-keyword presence checking.
Robots.txt Generator
Build a valid robots.txt with multiple user-agent groups, Allow/Disallow paths, Crawl-delay, Sitemap, and Host.
XML Sitemap Generator
Generate a sitemaps.org XML sitemap from a list of URLs, with optional lastmod, changefreq, and priority overrides per URL.
Schema Markup Generator
Generate valid JSON-LD for Organization, Person, Article, Product, FAQPage, BreadcrumbList, and WebSite.
HTTP Status Code Lookup
Look up any HTTP status code — meaning, category, RFC reference, and when to use it.
MIME Type Lookup
Look up the canonical MIME type for an extension, or extensions for a MIME type.
All Developer Tools
Cron Expression Parser
Translate a cron expression to plain English and preview the next five run times.
YAML Validator
Spot tab indent, unbalanced brackets, mixed sequences, and duplicate keys in your YAML.
Reverse Text Generator
Reverse text by characters, words, sentences, or lines — plus an upside-down flip.
Text Repeater
Repeat any text or phrase a chosen number of times with a custom separator.
Morse Code Translator
Encode text to ITU Morse code or decode Morse back into letters and digits.
ASCII Art Generator
Render short text as block-letter ASCII art with a built-in 5×5 bitmap font.
Linux Command Explainer
Break a Bash one-liner into commands, flags, args, pipes, and redirects with plain-English notes.
Cron Job Tester
Show the next N firing times of a 5-field cron expression in your local timezone.
About Developer Tools
Developer tools automate the repetitive transforms that surround real coding: pretty-printing data, validating syntax, converting between formats, generating boilerplate, and encoding or decoding values. A formatter parses input into a structured tree and re-serializes it with consistent indentation, surfacing syntax errors along the way. Converters map one representation onto another, such as turning a CSV row into a JSON object. Generators assemble valid config or markup from a few choices, and hashing tools run one-way functions over your input.
Consider the JSON Formatter. Paste a minified payload like {"id":1,"tags":["a","b"]} and it reparses the text, reports whether the structure is valid, and re-emits it with two-space indentation and sorted, readable nesting. If a comma or brace is missing, it points to the offending position instead of failing silently, which saves a round-trip through your editor.
Because these tools run client-side, sensitive payloads, tokens, and credentials never leave the browser. Output is only as correct as the input and the rules requested, so always review generated config, queries, or hashes before shipping them to production. Keep a copy of any generated configuration in version control so changes stay reviewable, and re-run the relevant validator whenever syntax rules, schema versions, or platform requirements shift over time.
Frequently asked questions
- What are developer tools used for?
- They format and validate code and data, convert between formats like JSON, YAML, and CSV, generate config and boilerplate for Docker, Nginx, and CI/CD, build database queries, and encode, decode, or hash values during development.
- When should I trust the output versus check it myself?
- Formatters and validators are reliable for syntax, but always review generated queries, config files, and hashes before using them in production. The tools speed up routine work; you remain responsible for correctness in your environment.
- Are the results correct and standards-compliant?
- Tools follow published specs for JSON, regex, Base64, JWT, and similar formats, so output is standards-aligned for typical input. Edge cases and unusual schemas may need manual adjustment, so verify results against your own requirements.
- Is my code or data sent to a server?
- No. Nothing is stored. Everything runs client-side in your browser, so source code, payloads, tokens, and credentials never leave your device or reach a server.
- Do these tools cost anything?
- No. Every developer tool is free and requires no signup, account, or payment. Open a tool, paste your input, and use the formatted, converted, or generated result immediately.