Free browser-based utilities
Make data easier
to work with.
Fast converters and calculators for developers, students, and everyday work. Your inputs stay right where they belong: in your browser.
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Popular tools
JSON Formatter
Format, validate, and beautify JSON instantly.
CSV to JSON
Convert CSV rows into clean JSON arrays.
Base64 to Text
Decode Base64 safely in your browser.
Mortgage Calculator
Estimate principal-and-interest mortgage payments after a down payment.
Markup & Margin Calculator
Compare gross profit, markup on cost, and margin on revenue.
Invoice & Estimate Generator
Create a copy-ready invoice or estimate with up to three line items, terms, tax, discount, and deposit.
Shipping Dimensional Weight Calculator
Compare actual and dimensional package weight with an editable carrier divisor.
Social Media Crop & Safe-Area Preview
Preview a centered social-media crop and overlay your own editable safe-area insets.
Video Bitrate, Duration & File Size Calculator
Solve for video file size, video bitrate, or duration using decimal media-storage units.
ISBN-10 & ISBN-13 Validator / Check-Digit Calculator
Validate ISBN-10 and ISBN-13 numbers or calculate a missing check digit from 9 or 12 digits.
Date Difference Calculator
Find the exact time between two dates.
Temperature Converter
Convert Celsius, Fahrenheit, Kelvin, and Rankine.
Paint Calculator
Estimate paint for the walls and optional ceiling of a rectangular room.
Flooring & Tile Calculator
Estimate floor area, order quantity, and full boxes with an editable waste allowance.
Concrete Slab Calculator
Estimate slab volume, bulk concrete, and whole bags for common mix sizes.
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Built for the work in front of you.
Data converters
65 focused tools
→02Document converters
18 focused tools
→03Text & encoding
45 focused tools
→04Developer tools
42 focused tools
→05Color converters
18 focused tools
→06File & internet
10 focused tools
→07Finance
5 focused tools
→08Date & time
4 focused tools
→09Unit converters
28 focused tools
→10Home improvement
6 focused tools
→11Business
17 focused tools
→12Publishing & media
16 focused tools
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More than an input box.
Practical guidance
Every tool explains what it changes, how to use it, and what to verify in the result.
Visible assumptions
Planning calculators label their inputs and show formulas and sources where outside guidance matters.
Clear privacy boundaries
Conversion inputs stay local, while our Privacy Policy separately explains hosting and advertising data.