Fast, private toolsthat never leave your browser
Utiliio 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.
Most online tools upload your data. We don't.
Every tool runs in your browser using JavaScript. Your JSON, tokens, configs, and passwords never touch our servers — no account, no logs, no upload.
Utiliio vs JSONFormatter.org — Which JSON Formatter Is Better?
Compare Utiliio and JSONFormatter.org for formatting JSON online. Privacy, speed, and features compared.
Utiliio vs Base64Encode.org — Private Base64 Encoding
Compare Utiliio with typical online Base64 encoders. Unified encode/decode workbench with URL-safe mode — tokens stay on your device.
Utiliio vs Online Cron Generators — Parse & Build With Next-Run Preview
Compare browser-based cron workbenches. Parse expressions with next-run preview and build schedules visually — no upload.
Browse by category
9 categories · 108 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.
17 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 converters
Free online converters — live output, no upload, runs in your browser
JSON to CSV Converter Online Free
Convert JSON arrays to CSV format
DeveloperJSON Formatter Online Free
Format, validate, and minify JSON with live error locations
Text ToolsASCII Decoder Online Free
Convert ASCII/Unicode codes back to characters
ConvertersHTML Encoder Online Free
Encode special characters to HTML entities
ConvertersUUID Generator Online Free
Generate RFC 4122 UUID v4 identifiers
GeneratorsJWT Decoder Online Free
Decode, inspect, and verify JSON Web Tokens
DeveloperSecurity & formatting tools
JWT, Base64, hashes, CSV parse, and HTML beautify — all private by default
More popular tools
JWT, formatting, encoding — all private by default
JSON Formatter
Format, validate, and minify JSON with live error locations
Text ToolsJSON to CSV
Convert JSON arrays to CSV format
DeveloperJWT Decoder
Decode, inspect, and verify JSON Web Tokens
DeveloperASCII Decoder
Convert ASCII/Unicode codes back to characters
ConvertersHTML Encoder
Encode special characters to HTML entities
ConvertersUUID Generator
Generate RFC 4122 UUID v4 identifiers
GeneratorsRecently added
Latest tools on the platform
Guides for popular tools
Step-by-step explainers linked to free browser tools
JSON to CSV Converter Online Free — Export Arrays to Spreadsheet
Convert JSON arrays to CSV online with live row counts, headers from keys, and CSV → JSON round-trip. Free, private, no upload.
Read guideJSON Formatter Online Free — Pretty Print & Validate JSON
Pretty-print, minify, and validate JSON online with live output, error locations, and structure preview. Free, private, no upload.
Read guideASCII Decoder Online Free — Convert Codes to Text
Decode ASCII and Unicode character codes to readable text. Decimal or hex input, live output — free, private, no upload.
Read guideHTML Encoder Online Free — Escape & Encode HTML Entities
Encode and decode HTML entities online instantly. Escape special characters for safe display — free, private, runs in your browser.
Read guideEvery tool, one platform
A growing library of browser-based utilities — showing 12 of 108 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
ConvertersASCII Decoder
Convert ASCII/Unicode codes back to characters
ConvertersAspect Ratio Calculator
Calculate width or height from aspect ratio
DeveloperBase64 Decoder
Decode and encode Base64 in one workbench
ConvertersBase64 Encoder
Encode and decode Base64 in one workbench
ConvertersBinary Converter
Convert text to binary and binary back to text
ConvertersBinary Decoder
Decode binary strings back to plain 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 Tools