ROI Calculator — Investment Return Tool

Generate time-based one-time passwords from a TOTP secret key. Enter your base32 secret, choose a period and digit length, and get the current and next codes with a live countdown timer. Useful for testing and debugging 2FA integrations.

Generate Zod validation schema code from a JSON sample object. Infers z.string(), z.number(), z.boolean(), z.array(), z.object(), and z.null() types automatically. Handles nested objects, arrays of objects with optional field detection, and outputs copy-ready TypeScript with import and z.infer type alias.

Format, validate, and inspect JSON Lines (JSONL) and NDJSON files. Validates each line individually, reports parse errors by line number, outputs compact JSONL or a pretty-print preview, and lets you download the cleaned file.

Calculate the information-theoretic bit entropy of any password or API key. Detects character set pools automatically, shows the total number of possible combinations, and estimates crack time across five attack scenarios from rate-limited web logins to GPU cracking clusters.

Calculate screen width and height from diagonal size and aspect ratio. Convert between inches and centimeters for displays, TVs, and monitors with instant dimension calculations.

Check TLS protocol version compatibility and cipher suite strength ratings against current best practices. Supports IANA and OpenSSL cipher names — rates each suite as Strong, Weak, or Deprecated and explains why.

Scan pasted text, code, or config files for accidentally exposed API keys, tokens, passwords, and private keys. Detects 50+ secret types across AWS, GitHub, Stripe, OpenAI, and more — all client-side, nothing leaves your browser.

Validate TOML configuration file syntax and report errors with line numbers. Paste any TOML content — Cargo.toml, pyproject.toml, config.toml — and instantly see a green checkmark with key counts and structure stats, or a precise error message pointing to the exact line. Includes a collapsible JSON structure preview to confirm what was parsed.

Calculate GST inclusive and exclusive prices. Add or remove GST with CGST, SGST, and IGST breakdown for Indian businesses.

Calculate Tax Deducted at Source (TDS) for Indian payments with automatic ₹ formatting

Calculate income tax payable and net income after tax with customizable tax rates and deductions

Calculate your monthly loan EMI (Equated Monthly Installment) with detailed breakdowns of principal, interest, and total payment.

Generate professional invoices for free. Create, customize, and download invoices with your business details, line items, taxes, and payment terms. Print or save as PDF instantly.

Build UTM tracking parameters for marketing campaigns. Generate tracked URLs with campaign source, medium, campaign name, term, and content parameters.

Generate professional receipts for free. Create, customize, and download receipts with your business details, itemized purchases, taxes, and payment methods. Print or save as PDF instantly.

Calculate monthly mortgage payment with principal, interest, property taxes, insurance (PITI), and HOA fees. Shows amortization schedule, total interest paid, and payoff date with extra payment scenarios.