Convert anything, in your browser.
172 free converters, calculators, and utilities. No upload, no account, no nonsense.
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Popular converters
The fast ones people actually use every day.
JSON to CSV Converter Pro
Convert JSON or NDJSON arrays into CSV with file drop, column reorder, flatten, and Excel BOM.
CSV to JSON Converter Pro
Convert CSV rows into a JSON array with file drop, header detection, and type inference.
Acres to Square Feet Converter
Convert acres to square feet using the standard 43,560 conversion factor.
Square Meters to Square Feet Converter
Convert square meters to square feet for floor area and property size.
Kilograms to Pounds Converter
Convert kilograms to pounds for body weight and shipping.
PNG to JPG Converter
Convert PNG images to JPG for smaller file sizes. HEIC/HEIF also supported.
Categories
Every toolbox, organized.
Developer Tools
Convert, format, validate, and clean developer data formats.
29
tools
Unit Converters
Convert area, length, weight, and other measurement units.
52
tools
Text Tools
Clean, transform, and format text quickly in your browser.
11
tools
Real Estate Calculators
Estimate cap rate, NOI, and other real estate metrics.
11
tools
Finance / Percentage Calculators
Calculate percentages, discounts, tips, and financial ratios.
9
tools
Construction Calculators
Estimate materials, dimensions, and construction quantities.
16
tools
Marketing Tools
Build campaign URLs and marketing utilities.
9
tools
Document Tools
Convert, merge, and prepare documents for sharing.
6
tools
Image Tools
Convert and prepare images for web and app use.
8
tools
Time & Date Tools
Convert time zones, calculate durations, and format dates.
6
tools
Design Tools
Generate colors, spacing scales, and design utilities.
6
tools
Kitchen / Recipe Tools
Scale recipes, convert measurements, and plan portions.
6
tools
Health & Fitness Calculators
Calculate BMI, daily calories, macros, and fitness metrics in your browser.
3
tools
Popular
Most-used tools this week.
Rental Property Deal Analyzer
Analyze rental deals with cap rate, cash flow, DSCR, and cash-on-cash in one dashboard.
Mortgage Calculator with Amortization
Calculate PITI payments, amortization schedules, extra payments, and home affordability.
JSON to CSV Converter Pro
Convert JSON or NDJSON arrays into CSV with file drop, column reorder, flatten, and Excel BOM.
CSV to JSON Converter Pro
Convert CSV rows into a JSON array with file drop, header detection, and type inference.
Nested JSON to CSV Converter
Flatten nested JSON objects into CSV using dot notation column keys.
JSON Formatter and Validator
Validate, pretty-print, and minify JSON with clear parse error messages.
Guides
Longer reads that link back to the tools.
What Is BMI? Body Mass Index Explained
Learn how body mass index is calculated, what WHO categories mean, and when BMI is a useful screening tool versus a misleading number.
BMI Categories and Limitations
Understand the full range of WHO BMI categories, obesity classes, population-specific cutoffs, and alternative metrics when BMI alone is not enough.
Understanding Cap Rate in Real Estate
Cap rate expresses net operating income as a percentage of property value—learn the formula, a full worked example, and how cap rate differs from cash-on-cash return.
TDEE and Calorie Deficits Explained
Learn how total daily energy expenditure is estimated with Mifflin-St Jeor, how activity multipliers work, and how to set a safe calorie deficit for weight loss.
Resources
Concept explainers that link back to the tools.
What Is an ICO File?
ICO is a Windows icon format that can store multiple sizes in one file—commonly used for website favicons and app shortcuts.
Standard Favicon Sizes Explained
A practical list of favicon dimensions browsers and platforms expect, and how to bundle them in one ICO file.
What Is JSON?
JSON is a lightweight text format for structured data—arrays, objects, strings, numbers, booleans, and null.
JSON vs CSV for Data Exchange
JSON preserves hierarchy and types; CSV is flat and spreadsheet-friendly. Choose based on your consumer.