Developer Tools
17 free browser-based tools — no signup, no limits, no cost.
All Developer Tools
17 toolsBulk Email Validator
Validate email addresses with 8 layers — RFC 5322 syntax, live MX lookup, SPF, DMARC, 750+ disposable domains, role detection, typo correction. Score 0–100 per email.
DNS Health Checker
Full DNS audit — checks A, AAAA, MX, NS, SPF, DMARC, DKIM, CAA, CNAME and SOA records. Live checks via Cloudflare. Health grade A+ to F with per-issue fix guidance.
JSON Formatter
Format and validate JSON
Base64 Encoder Decoder
Encode and decode Base64
CSS Gradient Generator
Generate CSS gradients visually
Password Generator
Generate strong passwords
QR Code Generator
Create QR codes instantly
JWT Decoder & Verifier
Decode any JSON Web Token, validate the signature (HS256, HS384, HS512, RS256) with your secret or public key. 100% client-side — your tokens never leave the browser.
cURL to Code Converter
Paste any cURL command — get equivalent code in fetch, axios, Python requests, Go, PHP, Ruby, Node http, Java OkHttp, .NET HttpClient and Rust reqwest. All client-side.
Regex Tester & Cheatsheet
Test JavaScript/PCRE regex live — see all matches, capture groups, replacement preview, full cheatsheet and common-pattern library. No paywall, no ads.
Data Format Converter
Bidirectional converter for CSV, JSON, YAML, TOML, XML and SQL INSERT statements. Drag a file or paste — switch formats instantly. Pure client-side.
Crontab Builder & Decoder
Build cron expressions visually, or paste any cron and get plain-English explanation + next 10 run times. Supports Vixie, Quartz, AWS and Kubernetes formats.
Timestamp & Timezone Converter
Convert Unix epoch ↔ ISO 8601 ↔ human-readable in any timezone. Includes a meeting planner that shows the same instant across up to 8 cities.
Hash Generator
Generate MD5, SHA-1, SHA-256, SHA-384, SHA-512 and HMAC hashes for any text or file — using Web Crypto API. Browser-side, your data never uploads.
UUID, ULID & NanoID Generator
Bulk-generate UUID v1/v4/v7, ULIDs, NanoIDs and Snowflake IDs — copy as JSON, CSV, SQL INSERT or plain list. 1 to 10,000 at once.
HTTP Status Codes Reference
Searchable database of every HTTP status code (100–599) with plain-English meanings, examples, retry strategies and RFC links. Daily reference for devs.
Cursor Rules & AGENTS.md Generator
Build a .cursorrules, AGENTS.md, .windsurfrules, CLAUDE.md or copilot-instructions.md file from a guided form — tell your AI coding assistant your stack and conventions.
What are Developer Tools?
FreeAIToolz offers 17 free developer tools — all browser-based with zero data storage and no account required. These tools include Bulk Email Validator, DNS Health Checker, JSON Formatter, Base64 Encoder Decoder and more. Every tool runs instantly in your browser and produces results in seconds.
Are these developer tools free?
Yes. All 17 tools in this category are 100% free with no premium tier, no word limits, and no signup required. FreeAIToolz is built on the principle that powerful tools should be accessible to everyone.