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Developer Tools

72 free developer tools. Browser-based. No signup. Privacy-first.

Free No signup Client-side Privacy friendly

What are Developer Tools?

Zerethon's developer suite includes 72 browser-based utilities designed for everyday developer workflows. Every tool runs entirely client-side — your input never reaches our servers.

Why client-side?

  • Privacy: sensitive data (API keys, payloads, passwords) never leaves your device.
  • Speed: no network round-trip — results appear as you type.
  • Reliability: works offline once loaded.
  • Cost: always free, no signup or rate limits.

Browse Developer Tools

Formatters & Minifiers · 18

JSON Formatter

Format, validate, and minify JSON online. Free, no signup — your data never leaves your browser.

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SQL Formatter

Format SQL queries online — beautify MySQL, PostgreSQL, SQLite, SQL Server, Oracle, and BigQuery.

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HTML Formatter & Minifier

Beautify or minify HTML in your browser. Pure client-side — your markup never leaves your device.

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CSS Formatter & Minifier

Beautify or minify CSS rules instantly in your browser. Free, no signup, no upload.

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YAML Formatter & Validator

Validate, reformat, and minify YAML in your browser. Catches syntax errors with line numbers.

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XML Formatter

Beautify or minify XML using your browser's native parser. No dependencies, fast and accurate.

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Markdown Formatter

Reformat Markdown with Prettier. Consistent spacing, list markers, and link layout.

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JavaScript Formatter & Minifier

Beautify with Prettier or minify in your browser. Supports modern syntax — async/await, optional chaining, JSX.

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Python Formatter

Clean up Python indentation, collapse blank lines, normalize string quotes. Indentation cleaner, not full PEP-8.

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PHP Formatter

Reformat PHP source in your browser. PSR-12-friendly defaults, brace-style toggle, opener normalization.

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Java Formatter

Reindent Java source with K&R or Allman brace style. Pure client-side, no compile.

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C# Formatter

Reformat C# source with Allman braces, auto-property normalization, and expression-bodied member tidy-up.

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C / C++ Formatter

Reformat C or C++ source — brace style, indent width, and preprocessor placement controls.

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Ruby / Lua / Perl Formatter

Reindent Ruby, Lua, or Perl source. One tool, three keyword-driven languages.

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GraphQL Formatter

Pretty-print GraphQL queries, mutations, and SDL using the official graphql/language parser.

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CSS Preprocessor Converter

Convert between LESS, SCSS, SASS, Stylus, and CSS. Real compilers for "to CSS" paths, heuristics for the rest.

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JavaScript Minifier

Minify JavaScript with terser. Mangle, compress, comment policies — and a before / after size comparison.

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HTML Minifier

Minify HTML with html-minifier-terser. Collapses whitespace, removes comments, inline CSS / JS minification. Size savings shown live.

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Data Converters · 14

CSV to JSON Converter

Convert CSV (or TSV / pipe-separated) data to JSON. Auto-detects delimiter, RFC 4180 compliant.

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JSON to CSV Converter

Convert a JSON array of objects to CSV. Optional dot-path flatten for nested data.

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JSON to YAML Converter

Convert JSON to YAML in your browser. YAML 1.2 spec.

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YAML to JSON Converter

Convert YAML to JSON in your browser. Catches syntax errors with parser messages.

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JSON to XML Converter

Convert JSON to XML in your browser. Configurable root element, attribute prefix, and text key.

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Delimited Text Extractor

Extract one column from CSV, TSV, or any delimited text. Pick by column number or header name. RFC 4180 compliant.

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XML to JSON Converter

Convert XML to JSON in your browser. Native DOMParser with configurable attribute prefix, text key, and compact mode.

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CSV to XML Converter

Convert CSV (or TSV / pipe-separated) data to XML. Configurable root and record element names. Header row becomes column tags.

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CSV to SQL Converter

Generate INSERT statements from CSV. MySQL, PostgreSQL, SQLite, or SQL Server dialect, with optional CREATE TABLE.

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HTML Stripper

Strip HTML tags and decode entities to plain text. Toggles for line breaks, links, and whitespace preservation.

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HTML Table Extractor

Extract <table> elements from HTML into CSV, TSV, JSON, or Markdown. Picks individual tables when the page has more than one.

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HTML to Markdown Converter

Convert HTML to Markdown using Turndown. ATX or Setext headings, bullet style, code-fence style — fully customizable.

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Markdown to HTML Converter

Render Markdown to HTML with live preview. GFM tables, task lists, fenced code blocks. Powered by marked.

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JSON to Java POJO

Generate a Java POJO from JSON. Toggles for Jackson annotations, Lombok, or Java 16+ records. Nested objects become nested classes.

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Frequently asked questions

Are these Developer tools free?

Yes. All 72 tools are free with no signup, no rate limits, and no ads outside footer placements.

Do these tools work offline?

Yes. Once a tool page loads, the tool itself runs in your browser without needing a network connection.

Do you log my inputs?

No. Tools run entirely client-side. Your input never leaves your browser unless a tool explicitly says it makes an API call (e.g. Open Graph Preview, which fetches a URL through our server proxy).

Can I use these tools commercially?

Yes. Outputs you generate are yours. The tools themselves are operated by Zerethon — please respect rate limits on server-backed tools.

Where can I request a new Developer tool?

Tweet us or open a GitHub issue. The most-requested tools enter our roadmap quarterly.

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