Free Online Developer Tools

Format, validate, and clean JSON with syntax highlighting.

Check JSON syntax errors and get precise error locations instantly.

Convert JSON arrays to CSV and CSV files back to JSON.

Generate TypeScript interfaces or types from JSON samples.

Encode text to Base64 or decode Base64 strings back to text.

Safely encode or decode URL strings and query params.

Decode JWT tokens and inspect headers and payloads client-side.

Encode special characters to HTML entities or decode them back.

Generate UUID v4 or timestamp-based v7 identifiers, format batches, and export them locally.

Create strong, random passwords with customizable options.

Create QR codes from text or URLs for quick sharing.

Convert titles into clean, SEO-friendly slugs with transliteration.

Design CSS gradients and copy the generated code.

Generate SEO, Open Graph, and Twitter Card meta tags.

Generate MD5 hashes from text for quick checksums.

Generate SHA256 hashes from text for integrity checks.

Test regular expressions with live matching and highlights.

Compare two texts side by side and highlight differences.

Write Markdown and preview the rendered HTML instantly.

Generate placeholder Lorem Ipsum text by words, sentences, or paragraphs.

Convert Unix timestamps to readable dates and back.

Convert colors between HEX, RGB, and HSL formats.

Convert images to Base64 data URIs for embedding.

Convert YAML to JSON and JSON back to YAML.

Format SQL queries with proper indentation and casing.

Minify CSS by removing whitespace, comments, and extras.

Minify JavaScript by stripping spaces, comments, and bloat.

Parse cron expressions and explain their schedules.

Convert text between uppercase, lowercase, title case, camelCase, and more.

Count words, characters, sentences, paragraphs and estimate reading time.

Remove duplicate and empty lines from your text lists.

Sort text lines alphabetically, numerically, or in random order.

Encode text to hexadecimal or decode HEX back to text.

Encode text to binary or decode binary back to text.

Format and beautify HTML code with proper indentation.

Minify HTML by removing whitespace, comments and extras.

Format and beautify XML code with proper indentation.

Generate SHA512 hashes from text for integrity checks.

Convert numbers to Roman numerals and vice versa.

Convert numbers between decimal, binary, hex, and octal bases.

Encode plain text to Unicode escape sequences or decode escaped text.

Escape and unescape JSON string content.

Escape or unescape text for safe regular expression usage.

Parse URLs into protocol, host, path, hash, and query parameters.

Parse query strings to JSON and build query strings from JSON.

Parse raw HTTP headers to JSON and build headers from JSON.

Search and reference common HTTP response status codes.

Analyze user-agent strings to detect browser, OS, and device.

Validate JSON documents against JSON Schema rules with detailed error paths.

Generate and verify HMAC-SHA signatures in hexadecimal or Base64.

Generate and verify OAuth PKCE S256 verifier and challenge pairs.

Calculate IPv4 networks, masks, broadcasts, and usable host ranges.

Resolve RFC 6901 pointers against JSON documents with precise path errors.

Convert Unix permissions between octal, symbolic, and checkbox forms.

Parse, normalize, and check HTTP Cache-Control directives.

Query JSON with paths, wildcards, slices, and recursive descent without evaluating scripts.

Build, normalize, and inspect Content Security Policy headers for common security gaps.

Build cURL requests or convert supported cURL input to JavaScript fetch without running commands.