Loading…
236+ free online tools across finance, math, health, unit conversion, text, and developer utilities. Pick a category below or search from the home page.
Format and validate JSON with proper indentation.
Decode JWT tokens and inspect header, payload, and signature locally.
Encode text to Base64 instantly with proper UTF-8 support.
Decode Base64 back to text instantly.
Test regex with live highlighted matches and a syntax cheat sheet.
Generate random v4 UUIDs for databases, sessions, and APIs.
Turn curl commands into JavaScript (Fetch/Axios) and Python requests code.
Turn Markdown into clean HTML with live preview.
Generate SHA-256 and SHA-1 hashes from text.
Decode binary back to readable text.
Convert text characters to binary representation.
Extract URL query parameters into a JSON object.
Estimate byte size of your text in various formats.
Remove all whitespace to minimize JSON size.
Convert CSV data to a JSON array using the header row.
Convert a JSON array of objects to CSV format.
Generate placeholder text for mockups and designs.
Generate random numbers in any range, with optional uniqueness.
Escape HTML special characters to prevent XSS attacks.
Convert HTML entities back to readable characters.
Encode text for safe use in URLs.
Decode percent-encoded URLs back to text.
Convert titles into clean, SEO-friendly URL slugs instantly.
Paste JSON and generate clean, nested TypeScript interfaces instantly.
Paste YAML and get clean, formatted JSON instantly.
Beautify SQL queries with clean indentation and uppercase keywords.
Turn an image into a Base64 data URI for inline embedding.
Compute netmask, network, broadcast, and host range from CIDR.
Convert between octal 755 and symbolic rwxr-xr-x permissions.
Decode user-agent strings into browser, OS, engine, and device.
Turn any JSON payload into a Draft-07 JSON Schema.
Convert names between camelCase, snake_case, kebab-case, and more.
Build a reverse proxy nginx server block with SSL and caching.
Format and indent minified HTML, CSS, JS, and JSON.
Paste options, spin, and let chance decide for you.
Inspect IP quality, ASN type, fraud score, and timezone consistency.
Convert Unix timestamps to dates and back, in UTC or local time.
Compare two JSON payloads field by field, order-insensitive.
Build a correct robots.txt with presets and live preview.
Press any key — see key, code, keyCode, and modifiers live.
Extension ↔ MIME type mapping for HTTP headers and configs.
Pretty-print, minify, or pinpoint-validate XML documents.
Grep-style filtering for logs — keyword, level, or regex.
Every ASCII character with dec/hex/oct/bin codes, searchable.
Craft signed JWTs locally — pairs with our decoder for testing.
Any base 2-36, fractions included, all common bases at once.
Click-to-build cron schedules with live plain-English preview.
301s, domain moves, HTTPS and canonical rules without tears.
Find any symbol by name or paste — code point and block shown.
Cargo/pyproject-style TOML parsed to clean JSON locally.
Calculate monthly payments, total interest, and full cost of any loan.
Calculate monthly mortgage payments and total interest.
See how your savings grow with the power of compound interest.
Convert APR to APY accounting for compounding frequency.
Calculate total and annualized return on investment.
See how your minimum payment splits between interest and principal.
Calculate true value of cash back rewards after annual fees.
Find your down payment amount and PMI status.
Calculate DTI ratio and see if lenders will approve you.
Calculate sales commission plus base salary.
Split a bill evenly including tip.
Find the monthly amount needed to reach any savings goal.
Calculate your net worth — assets minus liabilities.
Find annual and monthly payouts from a principal over N years.
Estimate capital gains tax on investments (short vs long-term rates).
Compare total cost of buying vs renting over a time period.
See how inflation reduces the value of money over time.
Project your retirement savings with compound growth.
Calculate simple interest with the I = Prt formula.
Compare unit prices to find the real best deal.
Find selling price and margin from cost and markup.
Convert your hourly wage to annual salary.
See how long to pay off your credit card balance.
Estimate US federal income tax and take-home pay.
Convert salary between annual, monthly, bi-weekly, and hourly.
Add or remove sales tax from any price instantly.
Calculate tips and split bills fairly among any number of people.
Find the final price after any discount and see how much you save.
Calculate car payments with down payment, trade-in, and tax.
See exactly what you net after eBay or Etsy fees.
Find how much to charge so you net exactly what you want.
Project HYSA growth with daily compounding and monthly deposits.
CD maturity value plus early-withdrawal penalty simulation.
Roth vs Traditional IRA, side by side — same dollars, different tax paths.
Your FIRE number, target retirement year, and savings-rate math in one screen.
What any appliance really costs per day, month, and year.
Gas money for any trip — one-way, round trip, split per person.
Total up every subscription and see the yearly damage.
Weekly pay with time-and-a-half, double time, or custom multipliers.
Estimate net pay after federal tax, FICA, and pre-tax deductions.
Turn your total into per-category amounts with typical percentages.
Full payment-by-payment schedule with running balance, CSV export.
Total ownership cost: fuel, insurance, maintenance, depreciation, financing.
Count words, characters, sentences, and reading time instantly.
Compare two texts and see what changed.
Join multi-line text into a single line.
Find and replace any text instantly.
Convert any text to ALL UPPERCASE instantly.
Convert any text to lowercase instantly.
Capitalize the first letter of each word for titles and headings.
Capitalize the first letter of each sentence automatically.
Convert URL slugs back to readable titles.
Remove all HTML tags to get clean readable text.
Count how often each character appears in text.
Pull all email addresses out of any text.
Pull all web links out of any text.
Add line numbers to each line of your text.
Add bullet points to each line of text.
Reverse any text — fun for puzzles and ciphers.
Clean up lists by removing duplicate lines while keeping order.
Sort any list alphabetically in one click.
Clean up messy spacing in any text.
Compare two lists to find unique and common items instantly.
Turn CSV/TSV data into GitHub-ready Markdown tables.
Strip emojis, accents, and special characters from text.
Shift subtitle timings by any offset and strip formatting.
Narrow down Wordle answers by known, included, and excluded letters.
Line-by-line diff with additions, deletions, and change counts.
Linked outline from your headings, GitHub-slug compatible.
Flesch scores and grade level with sentence-level breakdown.
Two-way Morse translation with dot-dash view and beep audio.
One-minute WPM and accuracy test — clean and ad-free.
Convert between metric, carats, and grains.
Convert between density units for physics and chemistry.
Convert between watts, kilowatts, horsepower, and BTU.
Convert between L/min, GPM, CFM and more flow units.
Convert between bytes, KB, MB, GB, TB and more.
Convert between seconds, minutes, hours, days and more.
Convert between binary, octal, decimal, and hex.
Convert between degrees, radians, and gradians.
Convert between MPG and L/100km for car efficiency.
Convert between bar, PSI, pascal, atm and more.
Convert between joules, calories, kWh, and BTU.
Convert between Hz, kHz, MHz, GHz, and RPM.
Convert between metric and imperial weight units instantly.
Convert between Celsius, Fahrenheit, and Kelvin instantly.
Convert between km/h, mph, m/s, knots, and ft/s instantly.
Convert between metric and imperial area units, including acres and hectares.
Convert between metric and US cooking volume units instantly.
Convert between metric and imperial length units instantly.
Cups ↔ grams ↔ ounces, adjusted per ingredient density.
Find trapezoid area from two parallel sides and height.
Find cube volume and surface area.
Find sphere volume and surface area from radius.
Convert numbers to scientific, E-, and engineering notation.
Check if any number is prime and find adjacent primes.
Decompose any number into its prime factors.
Calculate combinations (n choose r) for probability and odds.
Calculate permutations (arrangements where order matters).
Find circle area, circumference, and diameter from radius.
Solve right triangles — hypotenuse, area, perimeter.
Find rectangle area, perimeter, and diagonal.
Calculate standard deviation, variance, and mean.
Find the value at any percentile of your data.
Add, subtract, multiply, divide fractions with exact math.
Solve proportions and find missing ratio values.
Find LCM and GCD of any set of numbers.
Calculate mean, median, sum, min, max, and range of any number list.
Calculate percentages, increases, decreases, and discounts instantly.
Two-way Roman numeral conversion with a quick reference chart.
Calculate your Body Mass Index and see your healthy weight range.
Find your daily calorie needs for weight loss or gain.
Find your daily calorie needs (TDEE) for cutting, maintaining, or bulking.
Calculate calories your body burns at complete rest.
Estimate body fat % using circumference measurements.
Split daily calories into protein, carbs, and fat.
Estimate due date from your last menstrual period.
Find your ideal daily water intake.
Find your ideal body weight based on height and gender.
Pace, finish-time prediction, and split table for any race distance.
Daily protein target in grams, tuned to your weight and goal.
Bedtimes built around 90-minute sleep cycles so you wake refreshed.
Your five training zones, personalized with resting heart rate.
Estimate the caffeine still in your system right now.
16:8 / 18:6 / 20:4 schedules with countdown and metabolic timeline.
Steps → calories and distance, adjusted for your body.
Convert SVG to PNG or WebP in-browser with custom scale and download.
Convert pixels to rem and em with a custom root font size.
Compute missing width or height to keep any aspect ratio.
Test color contrast against WCAG AA and AAA accessibility levels.
Convert between HEX, RGB, and HSL with a visual picker.
Build OG and Twitter Card meta tags with a live social share preview.
Tune box-shadow and glassmorphism visually, preview live, copy the CSS.
Turn an image into 16x16, 32x32 favicons and an Apple Touch Icon.
Convert WebP images to PNG or JPG in your browser.
Convert PNG/JPG to WebP and see the size savings.
Resize and compress images with live file-size preview.
Strip comments, metadata, and whitespace from SVG files.
Build linear, radial, and mesh gradients with live preview.
Generate fluid font sizes with CSS clamp().
Estimate tokens and API cost for GPT and Claude prompts.
Per-request and monthly API costs across 17 models, side by side.
Rank every major model by your real monthly API bill.
Token count vs every model context limit, with headroom percentages.
Paste JSON, get a typed Zod schema — AI output validation ready.
Rescue malformed LLM JSON — truncated, trailing commas, fences.
Pull every ``` code block out of Markdown or AI answers.
Fill {{variables}} in prompt templates from JSON — live preview.
Form-built tool definitions → clean tools JSON for LLM APIs.
CSV training rows → OpenAI chat-format JSONL, mapped and validated.
Color-coded token boundaries with counts — see what models see.
Embedding costs across models: dimensions, $/1M tokens, workload totals.
Test your password strength with entropy analysis and a checklist.
Create strong, random, and secure passwords in one click.
Generate RSA or Ed25519 SSH key pairs in your browser.
Hash and verify passwords with bcrypt or salted SHA in-browser.
Generate high-entropy API keys and secrets in your browser.
HMAC-SHA256/384/512 signatures via native WebCrypto.
Constant-time comparison of two hashes — no timing leaks.
Entropy in bits — the honest measure of password strength.
AES-256-GCM in-browser: authenticated, PBKDF2-keyed, zero upload.
Turn a cron expression into plain English and see the next 5 fire times.
Calculate exact age in years, months, days, or time between any two dates.
Find exact duration between any two dates — days, weeks, months, business days.
Find the age gap between two people.
Convert times across zones and find meeting-friendly hours.
Live countdown to any date, or days between two dates.
Estimate reading and speaking time for any text.
Daily scrolling hours, translated into years of your life.
Create custom QR codes for URLs, text, and WiFi. Free, no watermark.
Model LTV, churn, CAC payback, and LTV:CAC for your SaaS.
Build, preview, and print professional invoices for free.
Break-even units, revenue, and contribution margin in one pass.
Cost + any one value → price, profit, margin, and markup.
CAC, LTV, payback months, and the LTV:CAC health gauge in one screen.
Roll any dice — d4 to d100, multiples at once, fair rolls.
A crisp instant heads-or-tails with a running tally.
Spin to decide: names, chores, restaurants — fairly chosen.
Fairly split any list into teams — reshuffle till it feels right.
Instead of hunting down a different website for every small job, ToolHub puts the utilities you reach for most in one place. Need to convert kilograms to pounds, calculate a mortgage payment, format a JSON payload, or generate a strong password? It is all here, and it all runs locally in your browser.
Every tool on this page is free with no signup and no upload. That means nothing you type ever leaves your device, which matters for sensitive inputs like salary figures, health numbers, or code snippets. Bookmark this page — we add new tools regularly based on what readers actually search for.