API Cost Estimator — Forecast Monthly Usage & Tiers

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.

Calculate DPI (dots per inch), image dimensions, and print sizes. Convert between pixels and physical dimensions for printing and displays.

Convert seconds to HH:MM:SS time format instantly with precise calculations and easy-to-read formatting.

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.

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.

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.

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.

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.

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.

Design and compare SaaS pricing tiers visually. Define plan names, monthly and annual prices, feature inclusions, and CTA text — then preview a live pricing table, copy it as embeddable HTML, and estimate MRR with a conversion rate and plan distribution calculator.

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.

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 how many months of cash runway your startup has. Enter your bank balance, monthly revenue, and monthly expenses to get net burn rate, runway in months, a status rating, and a month-by-month cash projection chart.

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.

Calculate Customer Acquisition Cost by channel. Enter marketing spend and new customers per channel to get blended and per-channel CAC, efficiency rankings, and a trend table to track how your CAC changes over time.

Calculate Annual Recurring Revenue, YoY growth rate, and net new ARR. Enter current and previous ARR (or MRR) with optional movement breakdown to get NRR and a visual ARR bridge.