Free Online Code Tools

Free online code tools — JSON formatters, Base64 encoders, JWT decoders, UUID generators, regex testers, hash generators, and more. No install, no sign-up.

JSON Formatter

Format, validate, and minify JSON data instantly.

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Base64 Encoder / Decoder

Encode plain text to Base64 or decode Base64 strings back to readable text instantly.

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URL Encoder / Decoder

Percent-encode URL components or decode %xx sequences back to readable text instantly.

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JSON to CSV Converter

Convert a JSON array of objects to CSV — all keys become headers, values properly escaped.

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CSV to JSON Converter

Convert CSV data to a JSON array of objects — handles quoted fields with commas.

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XML Formatter

Format and validate XML with 2-space indentation, or minify it — uses the browser's DOMParser.

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HTML Formatter

Beautify HTML with 2-space indentation or minify it — inline elements handled correctly.

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CSS Formatter

Format CSS with consistent indentation or minify it by stripping whitespace and comments.

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JavaScript Formatter

Format or minify JavaScript code with basic indentation — no external library required.

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UUID Generator

Generate cryptographically random UUID v4 values — up to 100 at once, copy individually or all.

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Hash Generator

Generate SHA-1, SHA-256, and SHA-512 hashes from any text using the Web Crypto API.

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JWT Decoder

Decode and inspect JWT header and payload — shows expiry status and issued-at time.

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Regex Tester

Test regular expressions with live match highlighting, flag toggles, and match position list.

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Cron Expression Generator

Build cron expressions from presets or type your own — get a plain-English explanation instantly.

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JSON to XML

Convert JSON data to XML format online.

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XML to JSON

Convert XML documents to JSON format online.

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YAML to JSON

Convert YAML to JSON format instantly.

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JSON to YAML

Convert JSON to YAML format instantly.

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SQL Formatter

Format and beautify SQL queries with consistent indentation — supports Standard, MySQL, PostgreSQL, BigQuery, and SQLite dialects.

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YAML Formatter / Validator

Parse, validate, and pretty-print YAML with clear error messages for invalid input — powered by js-yaml.

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.env File Generator / Parser

Paste KEY=VALUE pairs, view and edit as a table, re-export as .env — with a mask values toggle for safe sharing.

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Meta Tag Generator

Generate Open Graph, Twitter Card, and primary meta tags with live Google search and social card previews.

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robots.txt Generator

Form-based builder for User-agent, Allow, Disallow, and Sitemap rules — generates valid robots.txt output.

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.gitignore Generator

Searchable multi-select of tech stacks and tools — combines templates into one .gitignore file.

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JSON Diff Checker

Structural diff of two JSON inputs — recursively compare objects and highlight added, removed, and changed keys.

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Visual Regex Builder

Build regex patterns visually with checkboxes for common patterns — email, URL, digits, IP, dates — with live match highlighting.

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API Response Viewer

Paste a JSON API response and view it as a collapsible tree with type indicators per node.

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cURL Command Generator

Form-based builder for HTTP method, URL, headers, and body — generates the equivalent curl command string.

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HTML Entity Encoder / Decoder

Convert special characters to HTML entities and back — includes a reference table of common entities.

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CSS Box Shadow Generator

Sliders for x, y, blur, spread, color, and opacity — live preview and copy generated CSS.

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CSS Border Radius Generator

Per-corner sliders with live preview — link all corners or set each independently, px or % units.

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CSS Flexbox Playground

Visual controls for flex-direction, justify-content, align-items, flex-wrap, and gap — live preview with sample boxes.

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CSS Grid Generator

Visual grid builder with rows, columns, gap, and track template controls — live preview and copy CSS.

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Base32 Encoder / Decoder

Encode text to Base32 or decode Base32 strings back to text — pure JS RFC 4648 implementation.

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ASCII / Unicode Converter

Convert characters to their ASCII/Unicode code points and back — decimal, hex, or binary output with a reference table.

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Semantic Version Comparator

Input two semver strings, determine which is greater, and get a step-by-step explanation per semver rules.

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Slug SEO Checker

Analyse a URL slug for length, readability, stop words, hyphen usage, and get a simple SEO score.

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Advanced Slug Generator

Generate SEO-friendly URL slugs with stop-word removal — configurable stop-word list.

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