Free Online Tools
Fast, private, and no sign-up required. Calculators, converters, formatters, and more.
Categories
Calculators
Free online calculators for age, dates, percentages, discounts, and more.
10 tools
Formatters & Validators
Format, validate, and clean up JSON, text, code, and other data formats.
5 tools
Converters
Convert between file formats, units, encodings, and data types instantly.
10 tools
Finance
Free finance calculators for interest, loans, savings, tax, and more.
7 tools
Health & Fitness
Free health and fitness calculators — calories, body fat, ideal weight, and more.
5 tools
Developer Tools
Free developer and web utilities — password and UUID generators, color and hash tools, and more.
10 tools
Text Tools
Free text utilities — case converter, lorem ipsum, text diff, slug generator, and word frequency.
5 tools
Popular Tools
Jump right in — these are the most used tools.
Age Calculator
Calculate your exact age in years, months, and days instantly. Find out how old you are and when your next birthday is with our free online age calculator.
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Percentage Calculator
Calculate percentages quickly and easily. Find X% of Y, what percent X is of Y, or the percentage change between two numbers.
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Date Calculator
Calculate the number of days, weeks, and months between two dates or add and subtract days from any date. Free and instant.
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JSON Formatter
Format, prettify, or minify JSON data instantly. Paste your JSON and get clean, readable output with customizable indentation.
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Image to WebP Converter
Convert JPG, PNG, GIF, and other images to WebP format instantly. Adjust quality and reduce file size. Runs entirely in your browser.
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Just Added
The latest additions — new tools ship every week.
Random Number Generator
Generate random numbers in any range, with or without repeats. Uses your browser's secure random generator. Pick one number or a whole list.
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Fuel Cost Calculator
Estimate the fuel cost of any trip. Enter distance, your vehicle's efficiency, and fuel price — in US (MPG) or metric (L/100km) units.
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Final Grade Calculator
Find out exactly what score you need on your final exam to reach your target grade. Enter your current grade, goal, and the final's weight.
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GPA Calculator
Calculate your GPA on a 4.0 scale from your course grades and credit hours. Add each class, pick a letter grade, and get your weighted GPA instantly.
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Tip Calculator & Bill Splitter
Calculate the tip and split a restaurant bill between any number of people. Tip presets, per-person totals, and the full amount — instantly.
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Number Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal instantly. Handles very large values with no precision loss. Free and private.
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Cron Expression Parser
Paste a cron expression to see a plain-English breakdown of each field and the next 5 run times. Presets for common schedules included.
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URL Encoder / Decoder
Encode text for safe use in URLs, or decode percent-encoded strings back to plain text. Handles spaces, symbols, and Unicode. Free and private.
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Frequently Asked Questions
Are these tools really free?
Yes. Every tool on ToolNimbus is 100% free with no sign-up, no paywalls, and no usage limits.
Is my data sent to a server?
No. The tools run entirely in your browser, so your input never leaves your device.
Do I need to create an account?
No account is required. Open any tool and start using it immediately.
Can I use these tools on mobile?
Yes. Every tool is responsive and works on phones, tablets, and desktops.