ModernCalcs

Developer Tools

A collection of privacy-first, client-side tools for software engineers. Decode, format, and debug without your data ever leaving the browser.

JSON Formatter + Validator
Format, beautify, and deep-validate JSON syntax with line pointers.
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JSON ↔ CSV ↔ XML
Multi-way data converter for JSON, CSV, and XML formats.
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SQL Formatter
Beautify and clean up messy SQL queries for multiple dialects.
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Cron Expression Builder
Build and parse complex cron schedules with a visual interface.
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Regex Tester
Test Regular Expressions with real-time explanation and matching.
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JWT Decoder
Safely decode JWTs locally with claim explanations and metadata.
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URL Encoder / Decoder
Safely encode special characters for URLs or decode a URI component.
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Text Diff Checker
Compare two pieces of text side-by-side and highlight differences.
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CSS Unit Converter
Convert between pixels, rem, em, and viewport units instantly.
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UUID Generator
Bulk generate cryptographically secure Version 4 UUIDs.
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Base64 & Image Tool
Encode/decode text and images to Base64 Data URIs.
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IP Subnet Calculator
Professional CIDR tool for network range and host capacity.
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Time Zone Pro
Coordinate meetings with IST-focused presets for remote teams.
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Bandwidth Estimator
Calculate file transfer times and Mbps vs MB/s conversion.
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Curl to Code
Instantly convert curl commands to Python, JS, Go, and more.
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Professional-Grade Developer Utilities

Our Developer Tools hub is built for engineers who value speed and privacy. We provide a suite of tools for data formatting, security debugging, and network calculations that run entirely in your browser.

Data Manipulation & Formatting

Whether you need to beautify minified JSON, convert between CSV and XML, or format complex SQL queries, our tools handle large datasets with ease and consistency.

Testing & Debugging

Debug your Regular Expressions with our live Regex Tester, parse complex Cron schedules into human-readable text, or safely decode JSON Web Tokens (JWT) to inspect claims locally.

Why ModernCalcs for Developers?

  • Zero Backend: We don't have a server-side for these tools. Your data is 100% private.
  • Modern UI: Clean, responsive interface designed for professional productivity.
  • No Ads/Signup: No distractions, no trackers, just high-performance utilities.
  • Instant Results: Leverages local compute for lightning-fast transformations.