Fast, private toolsthat never leave your browser
Utilio is a free library of 100+ browser-based tools for developers and everyday tasks. Format JSON, encode data, calculate, convert — all processed locally with zero uploads.
Browse by category
9 categories · 102 tools available now
Text Tools
Format, analyze, and transform text directly in your browser.
27 tools
Converters
Encode and decode Base64, URLs, and other common data formats.
11 tools
Generators
Create UUIDs, passwords, and other random values instantly.
7 tools
Calculators
Quick calculators for finance, dates, and everyday math.
12 tools
Developer
Debug tokens, test regex patterns, and inspect developer data formats.
27 tools
Security
Generate cryptographic hashes and inspect security-related data.
5 tools
Math
Percentage, ratio, and everyday math calculators.
6 tools
Date & Time
Convert timestamps, timezones, and date values instantly.
3 tools
Network
CIDR calculators, HTTP references, and networking utilities.
4 tools
Popular tools
Most useful utilities to start with
Meta Tag Generator
Generate SEO and Open Graph meta tags
DeveloperCSS Gradient Generator
Create linear CSS gradients with live preview
DeveloperNaming Convention Converter
Convert between camelCase, snake_case, kebab-case, and more
DeveloperProfit Margin Calculator
Calculate profit margin and markup from cost and price
CalculatorsRandom Color Generator
Generate random colors with HEX, RGB, and HSL values
GeneratorsUUID Validator
Validate UUID format and identify version
DeveloperRecently added
Latest tools on the platform
Guides
32 guides · learn the concepts behind the tools
How to Create Markdown Tables
Syntax and tips for building tables in Markdown for GitHub, docs, and blogs.
Read guideProfit Margin vs Markup: What Is the Difference?
Learn how margin and markup differ and which to use when pricing products.
Read guideUUID Versions Explained (v1–v7)
Understand the different UUID versions and when each is used.
Read guideEssential Meta Tags for SEO and Social Sharing
Which meta tags every webpage needs for search engines and social previews.
Read guideEvery tool, one platform
A growing library of browser-based utilities — showing 12 of 102 tools below.
Add Line Numbers
Add line numbers to text and code
Text ToolsAge Calculator
Calculate exact age from a birthdate
CalculatorsASCII Converter
Convert characters to ASCII codes and back
ConvertersAspect Ratio Calculator
Calculate width or height from aspect ratio
DeveloperBase64 Decoder
Decode Base64 back to plain text
ConvertersBase64 Encoder
Encode plain text to Base64
ConvertersBinary Converter
Convert text to binary and binary back to text
ConvertersBMI Calculator
Calculate Body Mass Index from height and weight
CalculatorsCase Converter
Convert text to uppercase, lowercase, title, snake, and camel case
Text ToolsCharacter Frequency Counter
Count how often each character appears in text
Text ToolsChmod Calculator
Convert between octal and symbolic file permissions
DeveloperCIDR Calculator
Calculate subnet details from CIDR notation
Network