API Cost Estimator — Forecast Monthly Usage & Tiers

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.

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.

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.

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.

Generate a unique webhook URL and receive live HTTP requests. Inspect request headers, method, body, and timestamp in real time. No account required — payloads are stored temporarily for debugging.

Calculate gross and net burn rate by expense category. Enter monthly expense line items and MRR to get gross burn, net burn, cash efficiency ratio, and burn multiple — with a visual stacked breakdown showing where the money goes.

Build and send HTTP API requests directly from your browser. Set method, URL, query params, headers, and body (JSON, raw, or form-encoded). View the response status, headers, and body — and copy an equivalent cURL command for terminal use. Free, browser-based, no proxy.

Calculate Monthly Recurring Revenue from subscription plan tiers and customer counts. Get total MRR, ARR, ARPU, and a visual tier breakdown showing each plan's contribution.

Calculate your Net Promoter Score from promoter, passive, and detractor survey response counts. Get your NPS score (-100 to +100), category rating, and side-by-side benchmark comparison against 10 industries.

Calculate MoM, CAGR, and period-over-period revenue growth rates from a series of revenue figures. Get a visual growth rate chart, summary metrics, and a 3/6/12/24-month forward projection at your average or custom growth rate.

Compare two JSON objects and highlight differences. Perfect for debugging API changes and data transformations.

Calculate your Rule of 40 score by adding YoY revenue growth rate and EBITDA margin. See your tier (Elite / Healthy / Below Average), a visual gauge with the 40-point threshold, benchmark comparison against public SaaS companies, and a what-if table showing what growth or margin improvement is needed to reach 40, 50, or 60.