Hub Developer

Free developer tools

30 free developer tools that run in your browser. No account, no uploads, no watermarks.

The everyday utilities you reach for while debugging, without pasting anything into someone else’s server. That matters more than it sounds: production tokens, API responses and config files routinely get pasted into online formatters. Nothing on this page transmits what you paste.

All 30 developer tools

JSON Formatter Beautify, minify, sort keys, and validate JSON with live error detection. Download or copy output. Password Generator Generate cryptographically secure passwords with custom rules. Strength meter, bulk generation, download as .txt. Base64 Encoder / Decoder Encode text or files to Base64 and decode Base64 strings. File mode supports any file type with data URL export. Nothing is uploaded — all local. CRON Expression Builder Build and validate CRON expressions visually. See the next 10 scheduled execution times in plain English. CSS Minifier / Beautifier Minify CSS to reduce file size or beautify compressed stylesheets for readability. One click. CSV ↔ JSON Converter Convert CSV data to JSON and back. Preview as a table, customise delimiters, and download the result. DNS Lookup Check DNS records for any domain — A, AAAA, MX, TXT, CNAME, NS, SOA, CAA, and PTR. Uses Cloudflare's DoH API for fast, reliable results. Fake Data Generator Generate realistic test data — names, emails, addresses, IPs, UUIDs. Output as JSON, CSV, or SQL INSERT. Up to 100 records. Client-side. Hash Generator Generate MD5, SHA-1, SHA-256, and SHA-512 hashes from text or file inputs instantly in the browser. HMAC Generator Generate HMAC-SHA256, SHA-384, or SHA-512 signatures and verify webhook payloads. Runs entirely in your browser via Web Crypto API. HTML Entity Encoder Encode special characters to HTML entities (named, decimal, hex) and decode back. Clickable reference table. HTML Formatter Format and beautify messy HTML with proper indentation and tag nesting. Minify HTML to strip whitespace for production builds. HTTP Status Codes Searchable reference for all HTTP status codes — 1xx to 5xx. Filter by category, copy codes, and understand what each response means. JavaScript Minifier Minify JavaScript to cut file size by removing whitespace and comments. Beautify minified code back to readable. Shows savings percentage. JSON → CSV Converter Convert JSON arrays to CSV instantly. Choose delimiter, toggle quoting, and download the file. Handles missing keys and nested objects gracefully. JWT Decoder Decode JSON Web Tokens and inspect the header, payload, and signature. No server. No data stored. Markdown Preview Write Markdown and see the rendered HTML side-by-side in real time. Copy raw HTML output. Meta Tag Generator Generate SEO meta tags, Open Graph, and Twitter Cards. Preview how your page looks on Google and social media. OG Preview Tool Preview how your page looks when shared on Twitter/X, Facebook, LinkedIn, and Google Search. Generate meta tags instantly. Password Strength Checker Check password entropy and get a strength score with actionable tips to improve security. Regex Tester Write and test regular expressions with live match highlighting, group capture, and flags support. Robots.txt Generator Build a robots.txt file visually. Block AI bots, set crawl rules per user-agent, add sitemaps, and download. SQL Formatter Paste any SQL query and get it beautifully formatted — proper indentation, uppercase keywords, aligned clauses. Also minifies SQL. TOTP / 2FA Generator Generate and verify TOTP codes (RFC 6238) from a Base32 secret — the same codes used by Google Authenticator and Authy. Live countdown timer. URL Encoder / Decoder Percent-encode or decode URLs and query strings instantly. Supports Component mode (query values) and Full URL mode. Auto-encodes as you type. UUID / ULID Generator Generate cryptographically random UUID v4s or time-sortable ULIDs in bulk. Click any result to copy. What's My IP + Geolocation See your public IP with country, city, ISP, timezone, and coordinates. Look up any other IP address too. XML ↔ JSON Converter Convert XML to JSON or JSON to XML instantly. Handles attributes, arrays, and deeply nested structures. Swap sides with one click. XML Sitemap Generator Build an XML sitemap with lastmod, changefreq, and priority. Live XML preview, validate, and download instantly. YAML ↔ JSON Converter Convert YAML to JSON or JSON to YAML in real time. Swap panes, copy results, and see instant error messages.

How to use these tools

  1. Pick the tool you need from the list above — each one opens on its own page.
  2. Add your file or type your input. Nothing is uploaded; the work happens on your device.
  3. Adjust the options until the preview looks right.
  4. Download or copy the result. There is no watermark and no sign-up.

Frequently asked questions

Is what I paste sent anywhere?

No. Every tool here runs as JavaScript in your browser tab. Nothing you paste is transmitted, logged or stored, which is why these are safe for tokens, keys and production data.

Can I decode a JWT safely here?

Yes. The token is decoded locally in the page. It is never sent to a server, so a live session token does not leak by using the tool.

Do these work offline?

Yes, once loaded. The site is a progressive web app, so the tools keep working with no connection.

Is there an API?

No. These are interactive browser tools, not a hosted service.

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