Best Free Developer Tools
JSON, regex, Base64, JWT, UUID, YAML — developer utilities that stay local in the browser. Ranked for daily debugging and API work, not novelty. Bookmark JSON formatter and regex tester if you live in the terminal and browser DevTools.
⭐ Featured tools
All tools in this collection
CSV ↔ JSON Converter
Convert CSV tables to JSON and back
CSV to JSON Converter
Parse CSV rows into JSON array
Digital Skills Quiz & Certificate
Digital literacy quiz — 2FA, cloud, browsers, backups — with level certificate
Digital Tasbih Counter
Count dhikr with a simple digital tasbih
Docker Compose Generator
Starter docker-compose.yml
Event Schema Generator
Event structured data markup
Fake Data / Mock Generator
JSON mock users and products for tests
Fapiao A4 Two Per Page
Free online Fapiao A4 Two Per Page — fast, private browser tool on Fneno.com.
Fapiao Batch Renamer
Free online Fapiao Batch Renamer — fast, private browser tool on Fneno.com.
Fapiao Duplicate Checker
Free online Fapiao Duplicate Checker — fast, private browser tool on Fneno.com.
Fapiao Folder Organizer
Free online Fapiao Folder Organizer — fast, private browser tool on Fneno.com.
Fapiao OFD To PDF Converter
Free online Fapiao OFD To PDF Converter — fast, private browser tool on Fneno.com.
Fapiao PDF Merger A4
Free online Fapiao PDF Merger A4 — fast, private browser tool on Fneno.com.
Fapiao PDF To OFD Converter
Free online Fapiao PDF To OFD Converter — fast, private browser tool on Fneno.com.
Fapiao Stamp Adder
Free online Fapiao Stamp Adder — fast, private browser tool on Fneno.com.
Fapiao To Excel Extractor
Free online Fapiao To Excel Extractor — fast, private browser tool on Fneno.com.
Fapiao XML Parser
Free online Fapiao XML Parser — fast, private browser tool on Fneno.com.
FAQ Schema Generator
Build FAQPage JSON-LD for rich results
Git Commit Message Generator
Conventional Commits format builder
GitHub README Generator
README.md with badges & sections
HMAC SHA-256 Generator
Generate HMAC signatures for webhooks and APIs
HowTo Schema Generator
HowTo structured data with steps & supplies
HTTP Request Builder
Send GET/POST requests with headers and body
INI to JSON Converter
Parse INI config files to JSON
JSON Formatter Chinese Ui
Free online JSON Formatter Chinese Ui — fast, private browser tool on Fneno.com.
JSON to CSV Converter
Convert JSON array of objects to CSV
JSON to TypeScript
Generate TS interfaces from JSON
JSONPath Extractor
Query JSON with path expressions
JWKS JSON Validator
Validate JWK Set JSON for OIDC providers
JWT Generator (HS256)
Create signed JWT tokens with your secret
Offer Price Schema
Product Offer / price JSON-LD
OpenAPI Stub Generator
Build OpenAPI 3 YAML stubs for REST APIs
Organization Schema
Organization JSON-LD for knowledge panel
Product Schema Generator
Product JSON-LD for rich results
PWA Manifest Generator
Progressive Web App manifest.json builder
QAPage Schema Generator
FAQ rich results QAPage JSON-LD
Recipe Schema Generator
Recipe rich results JSON-LD
Regex Pattern Library
Common regex patterns with live test
RMB Capital Amount Converter
Free online RMB Capital Amount Converter — fast, private browser tool on Fneno.com.
Schema.org JSON-LD Generator
Create FAQ, Product, Organization structured data
Software Application Schema
App / SaaS JSON-LD markup
TOML to JSON Converter
Convert TOML config to JSON
Train Ticket Fapiao Parser
Free online Train Ticket Fapiao Parser — fast, private browser tool on Fneno.com.
UUID Generator
Generate RFC-compliant UUID v4 identifiers instantly
Video Schema Generator
VideoObject JSON-LD for YouTube embeds
XML Formatter
Format, validate, and minify XML documents
XML Sitemap Generator
Create XML sitemaps for better search indexing
YAML ↔ JSON Converter
Convert between YAML and JSON both ways
JSON Formatter
Format, validate and beautify JSON instantly
Find & Replace Tool
Find and replace text online — supports regex
Base64 Encoder / Decoder
Encode and decode Base64 strings instantly
JWT Decoder
Decode and inspect JWT tokens instantly
Regex Tester
Test regular expressions with live match highlighting
About this collection
❓ Frequently Asked Questions
We prioritize popularity signals (hot/new), coverage of the topic, and everyday usefulness — not paid placement.
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