Browse Tools by Category
Explore our suite of 46 client-side tools organized by engineering task.
JSON Utilities
4 toolsFormat, validate, query, sort, and escape raw JSON structures.
Data Converters
16 toolsSeamlessly convert between JSON, YAML, XML, CSV, TS interfaces, and C# class POCOs.
Web & Frontend
13 toolsURL encode/decode, HTML entity conversion, and Image-to-Base64 tools.
Security & Crypto
5 toolsCalculators for SHA-256 / SHA-512 hashes, JWT decoders, and secure string hashes.
Generators & Mocking
6 toolsInstantly bulk generate UUIDs (v4/v7), QR codes, and lorem ipsum placeholders.
Text & Utilities
9 toolsRegEx testers, side-by-side text comparisons, cron translators, and timestamp parses.
Popular Utilities
Quick access to our most frequently used developer utilities.
Format, validate against Schema, and minify JSON with smart fixes.
Format, beautify, and layout SQL database queries with custom dialect parameters.
Run in-browser SQL queries against CSV or JSON files with a custom query engine.
Safely encode special characters for query strings and URLs.
Convert images client-side between standard formats (PNG, JPEG, WebP, GIF, BMP).
Compress and optimize images locally to reduce file sizes.
Combine two images side-by-side or stacked with custom spacing and alignment.
Encode text or files to Base64 and decode Base64 strings
Decode and inspect JSON Web Token header, payload and signature
Generate customizable QR codes for URLs, Wi-Fi credentials, contact info.
Generate secure RSA public/private key pairs and SSH keys locally.
Hash passwords and verify text against Bcrypt hashes locally and securely.
Generate the exact Git commands for common workflow scenarios interactively.
Live interactive HTML viewer and previewer with sandbox isolation.
Why Professional Developers Choose Online & Offline Developer Tools
Modern software development requires handling highly sensitive parameters, proprietary configurations, and personal data daily. Standard web-based utilities like generic formatters, validators, and decoders often seem convenient. However, they introduce severe security risks by sending your input text directly to remote logging servers. If you paste a production JSON payload, database secrets, or API keys, that data is at risk of exposure.
100% Client-Side Privacy
Secure Devutils performs all conversions, format operations, and cryptographic hashing inside your browser using local web workers. Zero bytes of your source code, tokens, or personal configurations are transmitted over the network.
Online & Air-Gapped Offline Support
Engineered as a Progressive Web Application (PWA), this suite works fully both online and offline without requiring an active internet connection. You can execute high-security operations in secure, air-gapped corporate environments.
The Hidden Risks of Standard Online Dev Utilities
Every day, thousands of engineering keys, authentication tokens, and user records are leaked to malicious scraping servers disguised as free online utilities. Popular tools like jsonformatter.org and jwt.io are great for quick, non-sensitive tasks, but using them for confidential production APIs is a compliance liability. Secure Devutils acts as a secure, local-first alternative.
Key Privacy-First Developer Utilities Available Online & Offline
Secure Devutils offers a comprehensive workspace of 46 utilities organized to solve everyday developer hurdles online or completely offline without network overhead:
- JSON Formatter & Validator: Beautify complex nested payloads, validate syntax in real-time, execute schema queries, and run one-click smart repairs on broken JSON files.
- JSON Compare & Deep Diff: Perform side-by-side or unified semantic difference checks, calculate RFC 6902 JSON Patches, and filter identical keys instantly.
- JSON to C# Class Generator: Instantly convert JSON objects into C# classes, record structures, or strongly typed POCO objects with full support for properties, System.Text.Json, and Newtonsoft annotations.
- JSON Web Token (JWT) Decoder: Safely unpack header, claim payload, and signatures. Translate timestamp fields to localized calendar dates without sending authentication tokens across the internet.
- Base64 Encode & Decode: Safe UTF-8 string encoding, standard binary data conversion, and raw byte translations without server processing.
- Cryptographic Hash Generator: Calculate secure SHA-256, SHA-512, MD5, and SHA-1 checksum signatures for text and binary files locally utilizing the fast browser-native Web Crypto API.
- UUID & GUID Generator: Bulk generate cryptographically secure UUID version 4 and time-ordered version 7 identifiers using local browser entropy pools.
- Regular Expression (RegEx) Tester: Test matching capture groups and syntax validations against custom test cases in real-time, insulated from analytics logs.
PWA Technology: Air-Gapped Off-Grid Engineering
A Progressive Web Application (PWA) is the closest thing to a native desktop experience inside a browser wrapper. By caching all pages, assets, workers, and styles, PWAs enable applications to work seamlessly both online and offline without an internet connection. Once installed, Secure Devutils launches as a standalone sandbox program from your desktop dock or application menu, insulated from network telemetry and caching.
Frequently Asked Questions.
Find answers to common questions about our free online tools.