Developer Tools

Formatters, encoders, generators and testers every developer needs.

16 tools across 3 sub-categories

Code Formatters

Format and validate JSON, HTML, CSS.

6 tools

Regex Tester

Test JavaScript regular expressions live with match highlighting and capture groups.

Markdown Editor

Distraction-free markdown editor with live preview, auto-save and download.

JSON to YAML Converter

Convert JSON to clean, readable YAML — entirely client-side, no dependencies.

JSON ↔ CSV Converter

Convert JSON to CSV or CSV to JSON — handles quoted fields, embedded newlines and missing keys.

Markdown to HTML Converter

Convert Markdown to clean HTML with live preview — entirely in your browser.

JSON Formatter & Validator

Beautify, minify and validate JSON — entirely in your browser.

Code Generators

Passwords, UUIDs, regex, CSS.

4 tools

Slug Generator

Convert any title or phrase into a clean URL slug.

Cron Expression Builder

Write and decode cron expressions — with live plain-English explanation and presets.

UUID Generator

Generate version 4 UUIDs in bulk — using cryptographic randomness.

Password Generator

Generate strong random passwords with custom length and rules.

Encoders & Decoders

Base64, URL, JWT, hash.

6 tools

Base64 Encoder & Decoder

Encode any text to Base64 or decode Base64 back to text — UTF-8 safe.

URL Encoder & Decoder

Encode special characters for URLs or decode encoded URLs back to readable text.

Image to Base64 Converter

Convert any image to a Base64 data URL — for inline embedding in HTML, CSS or JSON.

HTML Encoder & Decoder

Escape HTML special characters or decode HTML entities back to text.

JWT Decoder

Decode JSON Web Tokens to inspect header and payload — entirely client-side.

Hash Generator (SHA family)

Generate SHA-1, SHA-256, SHA-384 and SHA-512 hashes from any text.

Converters that fit Developer Tools

Free in-browser converters from our full toolkit. Open one here or browse all in Converters.

24 tools

Password-Protect a ZIP

Converter

Build an AES-256 password-protected ZIP from any files. Compatible with WinRAR, 7-Zip, and macOS Archive Utility.

File Security

Text Decrypter

Converter

Decrypt base64 ciphertext produced by our Text Encrypter using its password. AES-256-GCM, browser-only.

File Security

File Decrypter

Converter

Decrypt a .enc file produced by our File Encrypter using its password. Runs in your browser, AES-256-GCM.

File Security

File Encrypter

Converter

Encrypt any file with a password using AES-256-GCM. Browser-only — files never upload. Output is a .enc file readable only with the same password.

File Security

Remove ZIP Password

Converter

Unlock a password-protected ZIP using its password and repack it without encryption. Browser-only.

File Security

Text Encrypter

Converter

Encrypt any text with a password. Output is a base64 string safe for email, SMS, or chat. AES-256-GCM, browser-only.

File Security

CSV to Excel Converter

Converter

Build a .xlsx workbook from CSV data. Handles quoted fields, embedded commas/newlines. Browser-only.

Excel Converters

CSV to Markdown Table Converter

Converter

Convert CSV to a properly-aligned Markdown table. Great for GitHub READMEs, docs, and Notion pages.

Data Converters

CSV to TSV Converter

Converter

Convert CSV to TSV. Tabs avoid CSV's comma-escaping pain and copy-paste cleanly into spreadsheets.

Data Converters

cURL to Fetch Converter

Converter

Convert curl commands to JavaScript fetch() code. Handles -X, -H, -d, -u, Authorization, JSON bodies.

Code Converters

Excel to CSV Converter

Converter

Convert .xlsx (or .xls / .ods) workbooks to clean CSV. Pick which sheet to export. Browser-only.

Excel Converters

Excel to HTML Table Converter

Converter

Convert a sheet to a styled HTML table. Live preview, copy or download as .html. Browser-only.

Excel Converters

Excel to JSON Converter

Converter

Convert an Excel workbook into a JSON array of row-objects. First row becomes the keys. Browser-only.

Excel Converters

File Hash Generator

Converter

Compute SHA-1, SHA-256, SHA-384, SHA-512 of any file. Verify downloads, dedupe files, check integrity. Browser-only.

File Security

HTML to JSX Converter

Converter

Convert HTML to JSX. Renames class → className, for → htmlFor, kebab-case SVG attrs to camelCase, inline styles to object form.

Code Converters

HTML to Markdown Converter

Converter

Convert HTML to clean Markdown. Powered by Turndown — preserves headings, lists, code blocks, links, blockquotes.

Markdown Converters

JSON to Excel Converter

Converter

Convert a JSON array of objects into a .xlsx workbook. Object keys become column headers. Browser-only.

Excel Converters

JSON to Go Struct Converter

Converter

Generate Go structs (with JSON tags) from any JSON sample. Nested objects become nested types.

Code Converters

JSON to Markdown Table Converter

Converter

Convert a JSON array of objects to a Markdown table. Union of keys becomes the header row.

Data Converters

JSON to TypeScript Interface Converter

Converter

Generate TypeScript interfaces from any JSON sample. Nested objects become nested interfaces; arrays become typed unions.

Code Converters

JSON to XML Converter

Converter

Convert JSON to XML in your browser. Object keys become tag names; arrays become repeated tags.

Data Converters

Markdown to HTML & HTML to Markdown

Converter

Round-trip Markdown ↔ HTML converter with live preview. CommonMark + GFM via marked; clean MD output via Turndown.

Markdown Converters

Markdown to Plain Text Converter

Converter

Strip all Markdown formatting and get clean plain text. Useful for word counts, exports, accessibility.

Markdown Converters

Query String to JSON Converter

Converter

Convert a URL query string to JSON. Handles repeated keys (arrays) and PHP-style bracket nesting like filters[year]=2026.

Code Converters

The everyday dev bench

Every developer keeps a drawer of small utilities open in a pinned tab — format this JSON, decode that token, generate a UUID. This niche is that drawer. The tools are deliberately fast and focused: paste, get the result, copy it back into your editor. Because everything runs client-side, you can safely paste an internal payload or a real JWT without it leaving your machine.

The JSON Formatter & Validator pretty-prints and catches the trailing comma that broke your API call, the JWT Decoder shows the claims inside a token without sending it to a third party, and the Base64 Encoder & Decoder handles data URIs and headers. For scaffolding, the UUID Generator and Cron Expression Builder save a trip to the docs.

Day-to-day tasks this covers:

Validating and reformatting messy JSON or YAML
Inspecting a JWT’s header, payload and expiry
Encoding/decoding Base64, URL and HTML strings
Testing a regular expression against sample text
Generating UUIDs, secure passwords and URL slugs

No telemetry, no signup, nothing uploaded. Free to use as often as your workflow demands.