# AnantAstra

> AnantAstra (https://anantastra.vercel.app) is an open-source, privacy-first web utility suite and technical knowledge base. Every calculator, converter, generator, and validator runs 100% client-side inside the user's browser using JavaScript and the Web Cryptography API. Zero data, sensitive inputs, financial numbers, or passwords are ever stored or transmitted to external servers.

AnantAstra is engineered with Next.js 15, React 19, Tailwind CSS v4, and shadcn/ui. The project is licensed under the MIT License and actively maintained on GitHub at https://github.com/Uniquearjav/anantastra.

## Core Privacy & Security Principles

- **Zero-Telemetry Guarantee**: All computations execute locally on the client thread. No remote API requests for user data.
- **Auditable Open Source**: Every tool implementation is public, transparent, and auditable on GitHub.
- **Zero Third-Party Trackers**: No intrusive tracking scripts, bloated ad networks, or user profiling cookies.
- **Cryptographic Rigor**: Password generation uses CSPRNG (`window.crypto.getRandomValues()`) rather than pseudo-random functions.

## Interactive Financial Calculators

- [Income Tax Calculator (FY 2025-26 & FY 2024-25)](https://anantastra.vercel.app/tools/calculator/income-tax-calculator): Indian income tax comparison engine between Old and New Tax Regimes. Evaluates the ₹75,000 standard deduction, Section 87A rebate up to ₹7.75 Lakhs, 80C/80D/HRA deductions, and marginal relief.
- [GST Calculator (Inclusive & Exclusive)](https://anantastra.vercel.app/tools/calculator/gst-calculator): Dual-mode Goods and Services Tax calculator for 0%, 5%, 12%, 18%, 28%, and custom rates. Computes CGST, SGST, IGST, base prices, and reverse tax extractions.
- [Loan EMI Calculator & Amortization](https://anantastra.vercel.app/tools/calculator/loan-emi-calculator): Equated Monthly Installment calculator for home, car, and personal loans using standard reducing-balance amortization schedules with monthly and yearly principal/interest charts.
- [SIP Wealth & Compounding Calculator](https://anantastra.vercel.app/tools/calculator/sip-calculator): Systematic Investment Plan compound interest projection engine calculating total invested capital, wealth gain, and inflation-adjusted maturity corpus.
- [Interest Calculator (Simple vs Compound)](https://anantastra.vercel.app/tools/calculator/interest-calculator): Comparative interest analysis engine supporting daily, monthly, quarterly, semi-annual, and annual compounding schedules alongside linear simple interest models.
- [Currency Exchange Converter](https://anantastra.vercel.app/tools/converters/currency-converter): Multi-currency foreign exchange calculator covering 160+ fiat currencies with offline fallback capability.
- [Number to Words Converter](https://anantastra.vercel.app/tools/converters/number-words-converter): Converts numbers to English words in Indian numbering format (Lakhs, Crores) and International format (Millions, Billions) with bank cheque formatting.

## Developer & Text Utilities

- [JSON Formatter & Validator](https://anantastra.vercel.app/tools/checkers/json-formatter): Secure, client-side JSON parser, validator, minifier, and interactive tree visualizer. Ensures sensitive API credentials and customer payloads never leave memory.
- [Text Difference & Diff Checker](https://anantastra.vercel.app/tools/code-text-tools/text-difference): Visual character, word, and line diff tool powered by the Myers Diff and Longest Common Subsequence (LCS) algorithms.
- [Markdown to HTML Live Converter](https://anantastra.vercel.app/tools/converters/markdown-html-converter): Real-time GitHub Flavored Markdown (GFM) editor with live HTML preview, table generation, and clean HTML code extraction.
- [SVG to PNG/WebP High-Res Converter](https://anantastra.vercel.app/tools/converters/svg-converter): In-browser vector rasterizer using HTML5 Canvas supporting 1x, 2x, and 4x retina export without quality degradation.
- [Morse Code Translator & Audio Player](https://anantastra.vercel.app/tools/converters/morse-code-converter): Bidirectional text-to-Morse and Morse-to-text converter with Web Audio API sound synthesis at customizable WPM and pitch.
- [Random Morse Code Audio Generator](https://anantastra.vercel.app/tools/code-text-tools/random-morse-generator): Morse code training tool supporting the Koch Method and Farnsworth Spacing for amateur radio (CW) ear training.
- [Physical Unit Converter](https://anantastra.vercel.app/tools/converters/unit-converter): Multi-unit physical dimension converter covering length, mass, temperature, digital storage (decimal GB vs binary GiB), volume, and speed.

## Security & Password Tools

- [Cryptographic Password Generator](https://anantastra.vercel.app/tools/password-tools/password-generator): Generates high-entropy passwords, Diceware passphrases, and PINs using `crypto.getRandomValues()` with real-time Shannon entropy and crack-time metrics.
- [Password Age & Rotation Checker](https://anantastra.vercel.app/tools/password-tools/password-age-checker): Credential hygiene auditing utility based on NIST SP 800-63B standards to evaluate rotation cycles without storing or transmitting passwords.

## Mathematical & Scientific Utilities

- [Prime Number Checker & Factorizer](https://anantastra.vercel.app/tools/checkers/prime-checker): High-speed primality testing engine combining trial division with the Miller-Rabin probabilistic algorithm for prime factorization and adjacent prime discovery.
- [Palindrome Symmetry Checker](https://anantastra.vercel.app/tools/checkers/palindrome-checker): Two-pointer linguistic and numeric palindrome verifier with character frequency metrics and nearest palindromic distance.
- [Leap Year Calendar Checker](https://anantastra.vercel.app/tools/checkers/leap-year-checker): Gregorian calendar validator demonstrating the 400-year exception rule (why 2000 was a leap year but 1900 and 2100 are not).
- [Arbitrary Precision Factorial Calculator](https://anantastra.vercel.app/tools/calculator/factorial-calculator): Exact factorial ($n!$), permutation ($P(n,r)$), and combination ($C(n,r)$) calculator utilizing JavaScript `BigInt` without floating-point overflow.
- [Decimal, Binary & Hexadecimal Calculator](https://anantastra.vercel.app/tools/calculator/decimal-binary-calculator): Multi-radix converter for Base 2, Base 8, Base 10, and Base 16 numbers with signed Two's Complement representation.
- [WHO Standard BMI Calculator](https://anantastra.vercel.app/tools/calculator/bmi-calculator): Body Mass Index calculator evaluating metric and imperial weight categories, healthy weight targets, and obesity classification.
- [Chronological Age & Biological Milestones](https://anantastra.vercel.app/tools/calculator/age-calculator): Chronological age calculation down to years, months, days, and seconds, with biological estimations for lifetime heartbeats and breaths.

## Technical Knowledge Base & Guides (25 Articles)

1. [New vs Old Tax Regime FY 2025-26 Guide](https://anantastra.vercel.app/blog/new-vs-old-tax-regime-fy-2025-26): Comprehensive comparison of Indian tax slabs, standard deduction increase to ₹75,000, Section 87A rebate up to ₹7.75 Lakhs, and salary breakeven benchmarks.
2. [GST Calculation Guide: Inclusive vs Exclusive Formulas](https://anantastra.vercel.app/blog/how-to-calculate-gst-inclusive-exclusive-formula): Mathematical derivation of forward GST addition and reverse GST extraction on commercial invoices.
3. [Home Loan EMI Formula & Amortization Secrets](https://anantastra.vercel.app/blog/home-loan-emi-calculation-formula-amortization): Analysis of reducing-balance interest formulas, principal-to-interest ratios, and prepayment strategies to save lakhs in interest.
4. [The Power of Compounding: ₹5,000 Monthly SIP to ₹1 Crore](https://anantastra.vercel.app/blog/sip-calculator-compound-interest-1-crore): Step-by-step mathematical model demonstrating how disciplined monthly investments grow via compound interest over 15 to 25 years.
5. [How Long to Crack Your Password: Entropy & GPU Hash Rates](https://anantastra.vercel.app/blog/how-long-to-crack-password-entropy-guide): In-depth review of password entropy, Shannon equations, NTLM/bcrypt cracking speeds on modern RTX 4090 clusters, and dictionary resistance.
6. [Why You Should Never Use Online JSON Formatters for Sensitive Data](https://anantastra.vercel.app/blog/why-offline-json-formatter-safer-for-developers): Security analysis of clipboard eavesdropping, server logging of API secrets, and the benefits of local browser parsing.
7. [Simple vs Compound Interest: Formulas & Real Examples](https://anantastra.vercel.app/blog/simple-vs-compound-interest-formula-guide): Side-by-side mathematical contrast between linear interest accumulation and exponential compounding frequencies.
8. [How to Write Numbers in Words on Cheques and Legal Invoices](https://anantastra.vercel.app/blog/how-to-write-numbers-in-words-cheque-rules): Formal grammatical and legal conventions for Indian banking (Lakhs/Crores) and International commerce (Millions/Billions).
9. [How to Convert SVG to PNG and WebP Without Losing Quality](https://anantastra.vercel.app/blog/svg-to-png-webp-conversion-retina-guide): Vector XML rasterization mechanics, viewBox preservation, device pixel ratios, and lossless canvas exports.
10. [International Morse Code: Alphabet, Sound Timing, & SOS](https://anantastra.vercel.app/blog/international-morse-code-alphabet-sound-guide): Complete ITU timing standards (1 dit unit, 3 dah units, 7 word units), mnemonic rhythms, and maritime distress history.
11. [Markdown to HTML Syntax Cheatsheet for Developers](https://anantastra.vercel.app/blog/markdown-to-html-syntax-developer-cheatsheet): Reference guide covering GitHub Flavored Markdown (GFM), table syntax, code blocks, task lists, and AST parsers.
12. [Binary, Decimal, and Hexadecimal Computing Guide](https://anantastra.vercel.app/blog/binary-decimal-hexadecimal-conversion-guide): Positional notation mechanics, binary bitwise logic, memory addressing in hexadecimal, and Two's Complement arithmetic.
13. [Healthy BMI Ranges for Men and Women](https://anantastra.vercel.app/blog/healthy-bmi-ranges-men-women-calculator-guide): Truth behind Body Mass Index, WHO cutoffs, limitations regarding muscle mass and athletic body composition, and body fat alternatives.
14. [How Leap Years Work: Why 2100 is NOT a Leap Year](https://anantastra.vercel.app/blog/why-2100-is-not-a-leap-year-calendar-math): Solar year drift calculations (365.2422 days), Gregorian calendar reform, and the 400-year century leap exception.
15. [Prime Numbers in Cryptography: RSA & Banking Encryption](https://anantastra.vercel.app/blog/prime-numbers-cryptography-rsa-encryption): Prime factor trapdoor functions, modular arithmetic, Euler's totient function, and the role of 2048-bit primes in TLS security.
16. [The Mystery of Palindromes: From Sator Squares to DNA](https://anantastra.vercel.app/blog/mystery-of-palindromes-literature-to-dna): Palindromic symmetry across ancient linguistics, computer science two-pointer algorithms, and genetic restriction enzyme recognition sites.
17. [Factorials and Permutations: 52! Deck of Cards Math](https://anantastra.vercel.app/blog/factorials-permutations-deck-of-cards-math): The mathematics of 52 factorial ($8.0658 \times 10^{67}$), Stirling's approximation, combinatorial explosion, and cryptographic entropy.
18. [How Text Diff Works: Myers Algorithm and LCS Explained](https://anantastra.vercel.app/blog/how-text-diff-myers-algorithm-works): Graph theory behind Eugene Myers' $O(ND)$ diff algorithm, edit graphs, Longest Common Subsequences, and Git diff generation.
19. [Data Storage Conversion: Why 1TB Shows as 931GB](https://anantastra.vercel.app/blog/why-1tb-hard-drive-shows-931gb-storage-guide): Decimal SI units ($10^{12}$ bytes) versus binary IEC units ($2^{40}$ bytes) and operating system file system accounting.
20. [Password Hygiene and Credential Rot: NIST SP 800-63B](https://anantastra.vercel.app/blog/password-age-hygiene-nist-credential-rotation): Why modern cybersecurity standards abandon arbitrary 90-day password resets in favor of length, passkeys, and threat-driven rotation.
21. [How Age Calculators Work: Precision & Biological Milestones](https://anantastra.vercel.app/blog/age-calculator-chronological-biological-milestones): Gregorian day counting algorithms, leap day adjustments, and estimating lifetime heartbeat and respiratory milestones.
22. [Currency Exchange Rates & Global Forex Markets](https://anantastra.vercel.app/blog/currency-exchange-rates-forex-markets-guide): Supply and demand dynamics, central bank interest rate differentials, purchasing power parity (PPP), and currency pairs.
23. [Text Case Conventions: camelCase, snake_case, kebab-case](https://anantastra.vercel.app/blog/text-case-converter-camelcase-snake-case-kebab-case): Software engineering naming conventions across JavaScript, Python, CSS, URL slugs, and database column names.
24. [Morse Code Generator & CW Audio Training Techniques](https://anantastra.vercel.app/blog/morse-code-generator-audio-training-techniques): Practical amateur radio ear training techniques including the Koch Method, Farnsworth timing, and rhythm recognition.
25. [Is AnantAstra Really Open Source? Privacy Architecture](https://anantastra.vercel.app/blog/is-anantastra-really-open-source): Architectural breakdown of AnantAstra's zero-telemetry client-side processing, MIT license, and open-source transparency.

## Machine-Readable & Discovery Endpoints

- [Dynamic XML Sitemap](https://anantastra.vercel.app/sitemap.xml): Complete, search-engine index of all tools, calculators, and articles.
- [Plain-Text Sitemap](https://anantastra.vercel.app/sitemap.txt): Direct line-by-line list of all canonical URLs.
- [JSON Sitemap API](https://anantastra.vercel.app/api/sitemap?format=json): Structured programmatic index returning paths, last modification dates, priorities, and change frequencies.
- [Robots Configuration](https://anantastra.vercel.app/robots.txt): Standard crawler directives permitting global indexing and referencing sitemap resources.
- [Deep Technical Documentation (llms-full.txt)](https://anantastra.vercel.app/llms-full.txt): Comprehensive technical breakdown with mathematical proofs, algorithm definitions, and complete code specifications.

## Metadata & Contact

- **Domain**: https://anantastra.vercel.app
- **Repository**: https://github.com/Uniquearjav/anantastra
- **License**: MIT License
- **Author**: Arjav & The AnantAstra Open Source Community