199 Free Dev Tools,
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Encoding & Decoding
JSON Formatter
Format, validate, and minify JSON with syntax highlighting.
Base64 Encoder / Decoder
Encode text or files to Base64, decode Base64 back to text.
URL Encoder / Decoder
Encode or decode URL components and query strings.
HTML Entity Encoder
Encode special characters to HTML entities or decode entities back to text.
String Escape / Unescape
Escape or unescape backslash characters and JSON strings.
Image to Base64 Converter
Convert images to Base64 data URIs for embedding in HTML/CSS.
SVG to CSS Converter
Convert SVG to CSS background-image data URI.
JSON Validator
Validate JSON syntax with detailed error messages and line numbers.
Base64 to Image
Decode Base64 strings back to images. Preview and download PNG, JPEG, SVG.
Generators
UUID Generator
Generate v4 UUIDs instantly. Bulk generate and copy with one click.
Cron Generator
Build cron expressions visually with human-readable descriptions.
Lorem Ipsum Generator
Generate placeholder text for mockups and designs.
Chmod Calculator
Visual Unix file permission calculator.
QR Code Generator
Generate QR codes from text or URLs.
URL Slug Generator
Convert titles to URL-safe slugs. Custom separators, stop word removal, batch mode.
Markdown Table Generator
Generate Markdown tables visually with an interactive editor.
Meta Tag Generator
Generate HTML meta tags for SEO and social sharing.
Twitter Card Preview
Preview and generate Twitter Card meta tags.
Crontab Guru
Advanced crontab expression editor with natural language explanations and next run times.
Flexbox Generator
Visual CSS Flexbox layout builder. Adjust properties and copy generated CSS code.
Security & Auth
Password Generator
Generate cryptographically secure random passwords.
Hash Generator
Generate SHA-1, SHA-256, SHA-384, and SHA-512 hashes from any text.
JWT Decoder
Decode and inspect JSON Web Tokens.
JWT Generator
Generate JSON Web Tokens with custom payload.
HTTP Headers Analyzer
Inspect and analyze HTTP request/response headers. Security header checker included.
Regex Cheat Sheet
Complete regex syntax reference with examples.
Text & Code
Regex Tester
Test regular expressions with real-time match highlighting.
Text Diff Checker
Compare two texts line-by-line.
Markdown Preview
Write Markdown and preview the rendered output.
CSS Minifier / Beautifier
Minify CSS to reduce file size or beautify it.
SQL Formatter
Format SQL queries with keyword uppercasing.
Text Case Converter
Convert between camelCase, snake_case, kebab-case, and more.
Markdown to HTML
Convert Markdown to clean HTML source code.
HTML Prettifier
Format and indent messy HTML code for better readability.
HTML to JSX Converter
Convert HTML to JSX with className, camelCase styles, and self-closing tags.
JavaScript Minifier
Minify JavaScript code to reduce file size.
JSON Path Finder
Navigate JSON structure and find paths to any value.
JSON to TypeScript
Convert JSON to TypeScript interfaces automatically.
SQL to MongoDB
Convert SQL queries to MongoDB query syntax. Supports SELECT, WHERE, JOIN, and more.
Text Counter
Count characters, words, sentences, and paragraphs.
JSON Diff
Compare two JSON objects and highlight structural differences. Nested diff support.
Converters
Timestamp Converter
Convert Unix timestamps to human-readable dates.
Color Picker
Convert colors between HEX, RGB, and HSL.
Number Base Converter
Convert between binary, octal, decimal, hex, and any base.
YAML / JSON Converter
Convert between YAML and JSON formats.
Epoch Batch Converter
Batch convert Unix timestamps to dates.
IP Address Lookup
Look up geolocation, ISP, timezone for any IP.
CSS Unit Converter
Convert between px, em, rem, pt, %, and vw.
JSON to CSV Converter
Convert JSON arrays to CSV or CSV to JSON.
Aspect Ratio Calculator
Calculate and convert aspect ratios for images and videos.
TOML Converter
Convert between TOML, JSON, and YAML formats. Perfect for Rust and Go config files.
Design & Reference
Placeholder Image Generator
Generate custom placeholder images with Canvas API.
HTTP Status Code Reference
Complete HTTP status code reference.
Tailwind CSS Color Generator
Generate full Tailwind CSS color palettes (50-950) from any base color.
Favicon Generator
Create letter-based favicons with custom colors. Download PNG in multiple sizes.
OG Image Preview
Preview how your page looks on Twitter, Facebook, and LinkedIn.
CSS Box Shadow Generator
Generate CSS box-shadow with visual controls and live preview.
CSS Gradient Generator
Create linear and radial CSS gradients with live preview.
CSS Grid Generator
Visual CSS Grid layout builder. Define rows, columns, gaps, and copy generated code.
Color Palette Generator
Generate harmonious color schemes.
Privacy Policy Generator
Generate GDPR/CCPA compliant privacy policy.
OG Debugger
Debug Open Graph tags by fetching any URL. Validate og:title, og:image, and more.
Calculators
BMI Calculator
Calculate Body Mass Index from height and weight.
Loan Calculator
Calculate monthly payments, interest, and amortization.
Mortgage Calculator
Estimate monthly mortgage payments with taxes and insurance.
Compound Interest
Calculate compound interest growth over time.
Retirement Calculator
Plan retirement savings with compound growth and 4% rule.
Income Tax Calculator
Estimate U.S. federal income tax with 2024 brackets.
Salary Calculator
Convert between hourly, weekly, monthly, and annual salary.
Pregnancy Due Date
Calculate due date from last menstrual period.
Sleep Calculator
Find best bedtime based on 90-min sleep cycles.
Body Fat Calculator
Estimate body fat % using U.S. Navy method.
Inflation Calculator
Calculate purchasing power change over time.
Concrete Calculator
Calculate cubic yards and bags for slabs and footings.
Paint Calculator
Calculate gallons of paint needed for a room.
Electricity Cost Calculator
Calculate appliance electricity costs per day/month/year.
Dog Age Calculator
Convert dog years to human years by breed size.
Age Calculator
Calculate exact age in years, months, and days.
Percentage Calculator
Calculate percentages and percentage change.
Calorie Calculator
Calculate daily calorie needs (TDEE).
Tip Calculator
Calculate tips and split bills.
Currency Converter
Convert between world currencies.
Date Calculator
Calculate days between dates.
Quadratic Formula
Solve ax²+bx+c=0 and find roots.
Probability Calculator
Calculate single and multiple event probability.
Pythagorean Theorem
Find the missing side of a right triangle.
Mean Median Mode
Calculate central tendency measures.
Standard Deviation Calculator
Calculate mean, variance, and standard deviation.
Scientific Calculator
Calculator with trig, log, and exp functions.
Fraction Calculator
Add, subtract, multiply, divide fractions.
Time Calculator
Add or subtract hours, minutes, seconds.
Percentage Change
Calculate percentage increase or decrease.
Ovulation Calculator
Predict ovulation and fertile window.
BAC Calculator
Estimate blood alcohol content.
Roof Pitch Calculator
Calculate roof pitch angle and ratio.
Area Calculator
Calculate area of various shapes.
Discount Calculator
Calculate discount prices and savings.
GPA Calculator
Calculate weighted GPA.
Speed Calculator
Calculate speed, distance, or time.
Fuel Cost Calculator
Estimate fuel cost for trips.
Time Zone Converter
Convert times between time zones.
Cat Age Calculator
Convert cat years to human years.
Financial Calculators
Compound Interest Calculator
Calculate compound interest with growth charts.
Amortization Calculator
Full amortization schedule with breakdowns.
ROI Calculator
Calculate return on investment.
Budget Calculator
Create monthly budget plan.
Net Worth Calculator
Calculate net worth from assets and liabilities.
Auto Loan Calculator
Calculate monthly car payments.
Savings Goal Calculator
Plan monthly savings to reach your goal.
401k Calculator
Estimate 401k balance at retirement.
Car Payment Calculator
Estimate monthly auto loan payments.
Student Loan Calculator
Estimate student loan payments.
Home Affordability
Find how much house you can afford.
Dividend Calculator
Calculate dividend yield and DRIP growth.
Refinance Calculator
Compare current vs refinanced mortgage.
Stock Return Calculator
Calculate stock investment returns.
Developer Tools
Subnet Calculator
Calculate subnet masks and IP ranges.
Color Contrast Checker
Check WCAG accessibility compliance.
Word Counter
Count words, characters, sentences.
Typing Speed Test
Test your WPM with accuracy tracking.
Storage Converter
Convert between KB, MB, GB, TB.
Tax & Salary
Tax Bracket Calculator
Find your federal tax bracket and effective tax rate.
GST Calculator
Calculate GST for inclusive/exclusive prices.
VAT Calculator
Calculate Value Added Tax.
Hourly to Salary
Convert hourly wage to annual salary.
Paycheck Calculator
Estimate take-home pay after taxes.
Marketing & SaaS Metrics
Conversion Rate Calculator
Calculate conversion rate from visitors.
CPM Calculator
Calculate cost per thousand impressions.
CPC Calculator
Calculate cost per click.
LTV Calculator
Calculate customer lifetime value.
Churn Rate Calculator
Calculate customer churn rate.
ROAS Calculator
Calculate return on ad spend.
Markup Calculator
Calculate markup from cost and price.
Margin Calculator
Calculate profit margin percentages.
Health & Lifestyle
Water Intake Calculator
Calculate daily water intake.
BMR Calculator
Calculate Basal Metabolic Rate and TDEE.
Ideal Weight Calculator
Calculate ideal body weight using multiple formulas.
Macros Calculator
Calculate daily macronutrient needs.
Pace Calculator
Calculate running pace and finish time.
Heart Rate Calculator
Calculate target heart rate zones.
Calories Burned Calculator
Estimate calories burned by exercise.
1RM Calculator
Estimate one rep max for any lift.
Protein Calculator
Calculate daily protein needs.
Home & Construction
Carpet Calculator
Calculate carpet area needed.
Drywall Calculator
Calculate drywall sheets needed.
Tile Calculator
Calculate tiles needed with grout.
Fence Calculator
Calculate fence materials needed.
Deck Calculator
Calculate deck boards and materials.
Gravel Calculator
Calculate gravel volume and weight.
Solar Panel Calculator
Estimate solar panel system size.
Mulch Calculator
Calculate mulch volume for gardens.
Pool Volume Calculator
Calculate pool water volume.
Wire Size Calculator
Calculate wire gauge for circuits.
Unit Converters
Sq Ft to Acres
Convert square feet and acres.
CM to Inches
Convert centimeters and inches.
Fahrenheit to Celsius
Convert Fahrenheit and Celsius.
Ounces to Grams
Convert ounces and grams.
Meters to Feet
Convert meters and feet.
Inches to Feet
Convert inches and feet.
Liters to Gallons
Convert liters and gallons.
Binary to Decimal
Convert binary and decimal numbers.
HEX to RGB
Convert HEX color codes and RGB.
Miles to KM
Convert miles and kilometers.
KG to LBS
Convert kilograms and pounds.
Shoe Size Converter
Convert shoe sizes between systems.
LBS to KG
Convert pounds and kilograms.
Cups to mL
Convert cups and milliliters.
MM to Inches
Convert millimeters and inches.
MPH to KPH
Convert speed: mph and kph.
Cooking Converter
Convert cooking measurements.
More Financial Tools
Break Even Calculator
Calculate your break-even point.
CD Calculator
Calculate CD interest and maturity value.
Credit Card Payoff Calculator
Calculate credit card payoff time and interest.
Debt Payoff Calculator
Plan your debt payoff strategy.
Debt To Income Calculator
Calculate your debt-to-income ratio.
Down Payment Calculator
Calculate down payment amounts.
Investment Calculator
Calculate investment returns over time.
Rent vs Buy Calculator
Compare renting vs buying a home.
Simple Interest Calculator
Calculate simple interest.
Hourly Paycheck Calculator
Calculate hourly paycheck after taxes.
Lifestyle & Planning
Age Difference Calculator
Calculate the age difference between two people.
Baby Due Date Calculator
Estimate your baby's due date.
Blood Type Calculator
Predict possible blood types of children.
Date Difference Calculator
Calculate days between two dates.
Pregnancy Due Date Calculator
Calculate pregnancy due date and milestones.
Ring Size Calculator
Find your ring size.
Wedding Budget Calculator
Plan and track your wedding budget.
Grade Calculator
Calculate your GPA and grades.
Gas Mileage Calculator
Calculate gas mileage and fuel costs.
Moving Cost Calculator
Estimate moving costs.
Electricity Cost Calculator
Calculate electricity costs for appliances.
More Tools
Bandwidth Calculator
Calculate bandwidth, transfer time, and file sizes.
Random Number Generator
Generate random numbers within a range.
Image Resize Calculator
Calculate image resize dimensions.
Screen Resolution Test
Test your screen resolution and display info.
Concrete Stairs Calculator
Calculate concrete needed for stairs.
Snow Load Calculator
Calculate snow load on roofs.
Soil Calculator
Calculate soil volume needed.
Square Footage Calculator
Calculate square footage of rooms and areas.
Privacy First
All processing happens locally in your browser. Zero data sent to servers.
Instant Results
No loading screens, no API calls. Results appear as you type.
Always Free
No freemium, no paywalls. Every tool is 100% free forever.