Developer & Security Utilities
Built for software engineers, DevOps practitioners, and security analysts, NexVaani Developer Utilities offer essential code formatting, decoding, and validation tools that run completely on your local workstation. Inspect sensitive JWT tokens, validate JSON payloads, test regular expressions, and generate cryptographic hashes without transmitting proprietary API keys or tokens across the network.
💻 Available Developer & Security Utilities (66)
100% Free & PrivateJSON Formatter & Validator
Format, validate, beautify, and inspect JSON data with syntax highlighting and tree view.
JSON Validator
Validate JSON syntax in real-time with line-by-line error messages and structure verification.
CSV to JSON Converter
Convert CSV spreadsheets and Excel data into formatted JSON arrays and nested objects offline.
Base64 Encoder & Decoder
Encode UTF-8 strings to Base64 or decode Base64 data into clean text with browser-based local processing.
Hash Generator (SHA-256, MD5)
Generate cryptographic hashes (SHA-256, SHA-512, SHA-1, MD5) directly inside your browser.
JWT Token Decoder
Decode and inspect JSON Web Tokens (JWT) headers, payloads, and claims offline in your browser.
JSON to CSV Converter
Convert JSON arrays and nested objects into tabular CSV spreadsheet files for Excel and Google Sheets.
UUID / GUID Generator
Generate cryptographically random RFC 4122 Version 4 UUIDs and GUIDs individually or in bulk.
Text & Code Diff Checker
Compare two text snippets or code files side-by-side to highlight additions, deletions, and character modifications.
Regular Expression Tester
Test and debug JavaScript regular expressions in real time with syntax highlighting and match capture groups.
Color Picker & Palette Generator
Inspect, convert, and harmonize colors across HEX, RGB, HSL, and CMYK formats with WCAG contrast checker.
HTML Minifier & Beautifier
Minify HTML markup by removing whitespace, comments, and line breaks to accelerate web page loading.
CSS Minifier
Minify CSS code by stripping whitespace, comments, and redundant semicolons to boost page speed.
JavaScript Minifier
Minify and compress JavaScript source code in your browser to reduce script payload sizes.
QR Code Scanner & Reader
Scan and decode QR codes instantly using your device webcam or by uploading image files.
Secure Password Generator
Generate strong, high-entropy cryptographic passwords with custom length, symbols, and numbers locally using Web Crypto API.
My IP Address Checker
Check your public IPv4/IPv6 address, ISP, location, and browser connection details instantly.
Number Base Converter
Convert numbers across Binary (Base 2), Octal (Base 8), Decimal (Base 10), and Hexadecimal (Base 16).
HTML Entity Encoder & Decoder
Encode special characters into HTML entities and decode HTML entities back to raw text.
URL Encoder & Decoder
Encode strings into percent-encoded URL formats (encodeURIComponent) and decode percent-encoded URLs.
Barcode & QR Studio
Generate Code 128 retail barcodes and 2D QR matrix codes with custom SKUs and high-resolution PNG export.
Digital Signature Generator
Draw digital signatures or generate stylish cursive calligraphy with transparent PNG download for PDFs and contracts.
JSON to CSV & CSV to JSON Converter
Convert JSON arrays to tabular CSV spreadsheets and CSV files back to JSON with syntax validation and instant download.
Cron Expression Builder & Tester
Build, validate, and decipher crontab syntax with human-readable explanations and upcoming schedule run times.
JSON to CSV / CSV to JSON Dual Converter
Bidirectional converter between JSON arrays and CSV spreadsheets with automatic nested object flattening and custom delimiters.
Unix Timestamp Converter
Convert Unix epoch timestamps to human-readable dates and convert calendar dates back to Unix timestamps in UTC and local time.
OpenAPI 3.1 & Swagger Spec Builder
Visually build OpenAPI 3.1.0 and Swagger API specifications with real-time YAML and JSON generation.
JSON Schema Generator & Validator
Automatically infer strict JSON Schema (Draft 2020-12 and Draft-07) from sample JSON payloads with type detection.
API Tester & HTTP Client (Postman Alternative)
Lightweight in-browser REST API and HTTP client. Test GET, POST, PUT, and DELETE requests with headers, payloads, and latency telemetry.
Regex Visualizer & Railroad Diagram
Deconstruct and visualize complex regular expressions as interactive railroad token diagrams with plain-English explanations.
Next.js & Tailwind Code Snippet Generator
Generate clean, production-ready code snippets for Next.js 15 App Router, React 19 hooks, and Tailwind CSS v4 components.
TypeScript Interface & Type Generator
Convert JSON objects into typed TypeScript interfaces, type aliases, and Zod validation schemas automatically.
YAML Formatter, Validator & JSON Converter
Format, validate, and convert YAML documents. Features bi-directional YAML ↔ JSON conversion and indentation controls.
File Size & Compression Ratio Diff Checker
Compare original vs optimized files to calculate byte-exact savings, reduction ratios, and CDN bandwidth economy.
Base64 Data String to File Reconstructor
Decode Base64 raw strings and Data URIs back into binary files with automatic MIME detection.
Split-Screen Markdown & KaTeX Live Studio
Live synchronous Markdown preview with GitHub Flavored Markdown tables, KaTeX math, and export options.
Code-to-Image Carbon Screenshot Maker
Render beautiful, high-resolution code snippet screenshots with custom gradients and macOS window frames.
Dynamic Custom QR Code & Logo Studio
Generate customizable QR codes with custom color palettes and centered brand logos.
NIST Password Entropy & Vulnerability Analyzer
Evaluate cryptographic bits of entropy, GPU brute-force resistance, and NIST SP 800-63B compliance.
Magic Bytes & MIME Header File Type Identifier
Detect the true binary identity and MIME type of files via magic byte inspection to expose spoofed file extensions.
Domain WHOIS & Live DNS Inspector
Inspect registrar details, active nameservers, and real-time DNS-over-HTTPS (DoH) resolution records.
Core Web Vitals & Lighthouse Speed Simulator
Measure real user telemetry for Google Core Web Vitals (LCP, INP, CLS, TTFB, FCP) in the browser.
Postman Collection v2.1 JSON Generator
Build compliant Postman Collections ready for 1-click import into Postman, Insomnia, or Thunder Client.
In-Browser GraphQL Playground & Explorer
Execute GraphQL queries, inspect variables, and test schemas with zero third-party telemetry.
ESLint Flat Config (v9+) Interactive Builder
Configure and export modern flat configuration files for Next.js, React, TypeScript, and Tailwind.
Safe In-Browser HTML Table & Data Scraping Parser
Extract, parse, and convert messy HTML web tables into structured CSV and JSON datasets locally.
OAuth 2.0 PKCE & JWT Token Studio
Generate RFC 7636 PKCE Code Verifiers, SHA-256 Code Challenges, and mock JWT Bearer tokens in your browser.
API Rate Limiter Visualizer & Simulator
Simulate Token Bucket and Leaky Bucket algorithms, burst capacity, and HTTP 429 backpressure handling.
Visual No-Code Event Workflow Builder
Design, test, and export conditional event pipelines and integration workflows.
Barcode Reader
Scan barcodes and QR codes from any image instantly using the browser's native decoder — no uploads, no ads.
Date to Unix Timestamp
Convert any calendar date and time into Unix epoch seconds and milliseconds, in local time or UTC.
DNS Lookup Tool
Query DNS records (A, AAAA, MX, TXT, NS, CNAME, SOA) for any domain via Google Public DNS and Cloudflare DNS over HTTPS.
Gravatar Checker
Check if any email address has a registered Gravatar profile, preview the avatar in high resolution, and copy the direct image URL.
Mailto Link Generator
Build mailto: links with pre-filled recipient, CC, BCC, subject line, and body text, plus ready-to-paste HTML anchor code.
MP3 Cutter & Audio Trimmer
Cut any audio clip to exact start and end seconds and export as MP3 or WAV — ringtone maker with zero server upload.
PayPal Link Generator
Build PayPal.me payment links with pre-filled amount and currency for client invoices, tips, donations, and freelance services.
Ping Test
Test website latency and response time from your browser with 5-sample ping, jitter, and status codes.
SSL Certificate Checker
Check any domain's SSL/TLS certificate: issuer, validity dates, expiry countdown, and covered SAN hostnames — free and instant.
Timetable Maker
Build a printable weekly timetable or class schedule that auto-saves in your browser — free and no account needed.
Unix Timestamp to Date
Convert Unix epoch seconds or milliseconds to readable UTC, local, and ISO dates with relative time ('5 minutes ago').
URL Extractor
Pull every http/https link out of any text, HTML, or log file with automatic cleanup, sorting, and deduplication — free and private.
URL Parser
Break any URL into protocol, host, port, path, hash, and a decoded table of every query parameter — free and private.
User Agent Parser
Decode any User-Agent string into browser, engine, OS, and device type — and see your own browser's UA string instantly.
WhatsApp Link Generator
Create wa.me click-to-chat links with a pre-filled message for customer support, sales, and social media bios.
Wheel of Decision
Spin a customizable decision wheel with your own options — fair crypto-random picks for classes, giveaways, and dinner.
YouTube Timestamp Link Generator
Create YouTube links that open at an exact minute and second — perfect for sharing the best moment of any video.