A directory of free, no-signup tools, calculators, and converters
45 free tools across 6 focused sites. No accounts, no installs, and nothing you type is uploaded.
Developer Tools
Converters
Calculators
Text Tools
Find the right tool
Each site in the directory focuses on one kind of job, so its tools can go deeper than a general-purpose utility page. If you're working with code or data, Dev Toolkit covers formatting and validating JSON and YAML, decoding JWTs, testing and generating regular expressions, and building cron schedules. For writing and editing, Text Toolkit counts words, converts capitalization, compares drafts, and cleans up lists.
For numbers with units, Unit Converter handles everyday measurements from recipes to tire pressure, and Currency Converter uses live exchange rates, with reference pages for 40 currencies and the pairs people convert most. Payment Calculator is for borrowing decisions, showing the full cost of a mortgage, refinance, car loan, or credit card balance rather than only the monthly payment. Pregnancy Toolkit covers due dates, trimesters, and tracking kicks and contractions.
Every site also has a guides section explaining the concepts behind its tools, such as why early mortgage payments are mostly interest, how currency pegs work, or how diff algorithms decide what changed. All the tools run in your browser, which keeps them fast and keeps your data on your device.
Every tool
Dev Toolkit
- JSON Formatter: Format, validate, and minify JSON with clear error messages.
- Base64 Encode/Decode: Encode text to Base64 or decode Base64 back to text, with full UTF-8 support.
- JWT Decoder: Decode a JWT's header and payload instantly, entirely in your browser.
- Regex Tester: Test regular expressions against sample text with live match highlighting.
- Regex Generator: Generate ready-to-use regular expressions for common patterns like email, URL, and phone number.
- Cron Expression Builder: Build and explain cron expressions in plain English, with upcoming run times.
- YAML ↔ JSON Converter: Convert between YAML and JSON instantly, both directions.
- UUID Generator: Generate one or many random UUID v4 values with formatting options.
- Unix Timestamp Converter: Convert between Unix timestamps and human-readable dates across timezones.
- URL Encoder/Decoder: Encode or decode URLs and URI components safely.
- Diff Checker: Compare two blocks of text and see additions and deletions highlighted.
Text Toolkit
- Markdown ↔ HTML Converter: Convert Markdown to HTML or HTML back to Markdown, with a live preview.
- Word Counter: Count words, characters, sentences, and paragraphs, plus estimated reading time.
- Case Converter: Convert text between UPPERCASE, Title Case, camelCase, snake_case, and more.
- Find and Replace: Find and replace text in bulk, with optional case sensitivity and regex support.
- Line Sorter and Deduplicator: Sort, deduplicate, shuffle, or clean up a list of lines.
- Lorem Ipsum Generator: Generate placeholder Lorem Ipsum text by paragraphs, sentences, or words.
- Diff Checker: Compare two blocks of text and see additions and deletions highlighted.
Unit Converter
- Length Converter: Convert between millimeters, meters, feet, miles, and more.
- Weight & Mass Converter: Convert between milligrams, grams, kilograms, ounces, pounds, and tons.
- Temperature Converter: Convert between Celsius, Fahrenheit, and Kelvin.
- Volume Converter: Convert between milliliters, liters, gallons, cups, and more.
- Area Converter: Convert between square meters, square feet, acres, hectares, and more.
- Speed Converter: Convert between mph, km/h, m/s, and knots.
- Time Converter: Convert between seconds, minutes, hours, days, and years.
- Digital Storage Converter: Convert between bits, bytes, KB, MB, GB, and TB.
- Pressure Converter: Convert between pascals, bar, PSI, and atmospheres.
- Energy Converter: Convert between joules, calories, watt-hours, and BTU.
Currency Converter
- Currency Converter: Convert between 40 world currencies at the live mid-market rate.
- Popular Currency Pairs: USD to EUR, GBP to USD, USD to INR, and other common pairs, each with a two-way conversion table.
- World Currency Reference: Symbols, subunits, central banks, and exchange rate regimes for 40 currencies.
Payment Calculator
- Mortgage Calculator: Estimate your monthly mortgage payment including principal, interest, property tax, home insurance, PMI, and HOA fees.
- Home Affordability Calculator: Find out how much house you can afford from your income, debts, and down payment, using the 28/36 debt-to-income rule lenders use.
- Refinance Calculator: See whether refinancing your mortgage saves money: new payment, monthly savings, break-even point on closing costs, and lifetime interest.
- Loan Calculator: Calculate monthly payments and total interest for any fixed-rate loan: auto, personal, student, or other.
- Auto Loan Calculator: Calculate your car payment including sales tax, fees, trade-in, and negative equity, and compare 36- to 84-month terms side by side.
- Credit Card Payoff Calculator: See how long it will take to pay off a credit card balance and how much interest you'll pay, or find the monthly payment needed to be debt-free by a target date.
Pregnancy Toolkit
- Due Date Calculator: Estimate your baby's due date from your last menstrual period, or work backward from a due date.
- Pregnancy Week Calculator: Find out exactly how many weeks and days pregnant you are, with a progress bar and development milestones.
- Baby Name Generator: Generate baby name ideas by gender and style, with meaning, origin, and popularity for each.
- Conception Date Calculator: Estimate your likely conception window from a due date, or forward from your last period.
- Trimester Calculator: See the exact date range for each trimester, which one you're in now, and what to expect.
- Baby Due Month Predictor: Find your baby's likely birth month, zodiac sign, and general seasonal considerations.
- Kick Counter: Time how long it takes to feel 10 baby movements, and keep a log of past sessions.
- Contraction Timer: Time your contractions and track duration and frequency as labor progresses.