Free online tools

UtilBento free browser utilities

UtilBento is a small collection of fast, free online tools for developers, writers, date calculations, money estimates, favicons, and file conversions. Most tools run locally in your browser with no signup.

Available tools

• Timestamp Converter - Convert Unix timestamps, millisecond timestamps, ISO strings, UTC time, and local dates without sending your data to a server.
• JSON Formatter - Format, minify, validate, and copy JSON in your browser for API debugging, config cleanup, and quick data review.
• CSV to JSON Converter - Convert CSV to JSON arrays or objects with delimiter choices, header detection, copy, and download options.
• Markdown Table Generator - Generate GitHub-ready Markdown tables from CSV-like rows, tabs, or semicolon-separated data.
• Date Difference Calculator - Calculate the difference between two dates in calendar days, weeks, approximate months, and approximate years.
• Age Calculator - Calculate exact age from a birth date in years, months, days, total days, and next birthday countdown.
• Salary to Hourly Calculator - Convert annual salary to hourly, weekly, biweekly, and monthly pay with adjustable hours per week and weeks per year.
• Compound Interest Calculator - Estimate compound interest growth with principal, annual rate, years, monthly contributions, and compounding frequency.
• Image to ICO Converter - Convert PNG, JPG, or WebP images into a multi-size favicon.ico file locally in your browser.
• Favicon Generator - Generate simple text, letter, or emoji favicons with custom colors and downloadable PNG output.

Popular guides

• JSON Formatter Online Free: Format, Validate, and Minify JSON - Learn when to format, validate, or minify JSON, then use UtilBento's free browser-based JSON formatter for API responses and config snippets.
• CSV to JSON with Headers: Convert Spreadsheet Rows to Objects - Turn CSV rows into JSON objects using the first row as headers, with tips for quoted cells, delimiters, and clean API mock data.
• Unix Timestamp in Milliseconds: Convert 13-Digit Epoch Time - Understand the difference between Unix seconds and milliseconds, then convert 10-digit and 13-digit timestamps into readable dates.
• Markdown Table Generator for GitHub README Files - Create GitHub-ready Markdown tables from CSV, tab-separated rows, or copied spreadsheet data without manually aligning pipes.
• Days Between Dates Calculator: Count Calendar Days Quickly - Calculate days between two dates for deadlines, trips, launches, subscriptions, and project planning.
• Salary to Hourly Calculator for a 40-Hour Work Week - Convert annual salary to hourly pay using a 40-hour week, then compare weekly, biweekly, and monthly gross pay.
• PNG to ICO Favicon Converter for Website Icons - Convert a PNG logo into a multi-size favicon.ico file with common 16, 32, and 48 pixel icon sizes.
• Favicon Generator from Text, Letters, or Emoji - Create a simple text favicon from initials, letters, or emoji with custom foreground and background colors.
• Exact Age Calculator in Years, Months, and Days - Calculate exact age from a birth date in years, months, days, total days lived, and next birthday countdown.
• Compound Interest Calculator with Monthly Contributions - Estimate compound growth with a starting amount, monthly contribution, annual rate, years, and compounding frequency.
• JSON Minify Online: Compress JSON for Copy and Paste - Minify JSON online for compact config fields, test payloads, API examples, and quick copy-paste workflows.
• Tab-Separated CSV to JSON Converter - Convert tab-separated spreadsheet rows into JSON arrays or objects with header row support.
• Timestamp to Date Converter: UTC and Local Time - Convert Unix seconds, Unix milliseconds, and ISO timestamps into readable UTC and local dates.
• CSV to Markdown Table Generator - Convert comma-separated rows into a clean Markdown table for GitHub README files, docs, issues, and notes.
• Markdown Table Syntax for GitHub README Files - Learn the basic Markdown table syntax used in GitHub README files and generate a ready-to-copy table.
• Markdown Table Alignment: Left, Right, and Center Columns - Understand Markdown table alignment syntax and generate tables that render cleanly in GitHub and docs.
• How to Escape Pipe Characters in Markdown Tables - Fix Markdown tables that break when cell text contains the pipe character by escaping pipes correctly.
• JSON Formatter vs JSON Validator: What Is the Difference? - Compare JSON formatting, minifying, and validation so you know which action to use when debugging API data.
• CSV to JSON Array of Objects - Convert CSV rows with headers into a JSON array of objects for mock APIs, docs, fixtures, and prototypes.
• ISO 8601 to Timestamp Converter - Convert ISO 8601 date strings into Unix seconds, Unix milliseconds, UTC time, and local time.
• Epoch Time Converter for API Logs - Convert Unix epoch times from API logs into readable dates while checking seconds, milliseconds, UTC, and local time.
• JSON Pretty Print API Response - Pretty print an API response so nested JSON objects, arrays, and fields are easier to inspect.
• JSON Quotes and Backslashes: Common Syntax Fixes - Learn why JSON strings need double quotes, escaped quotes, and careful backslashes before formatting or validating.
• CSV Delimiters: Comma, Semicolon, and Tab to JSON - Choose the right CSV delimiter before converting spreadsheet exports into JSON arrays or objects.
• Days Until Date Calculator - Count how many days remain until a deadline, event, launch date, trip, or renewal date.
• Calculate Age on a Specific Date - Find someone's exact age on a future or past date in years, months, days, and total days.
• Annual Salary to Monthly Pay Calculator - Convert annual salary into estimated monthly, weekly, biweekly, and hourly gross pay.
• Daily vs Monthly vs Annual Compound Interest - Compare how compounding frequency changes estimated growth over time.
• Favicon Sizes for Websites - Understand common favicon sizes such as 16x16, 32x32, 48x48, 180x180, and 512x512 before generating icons.
• JPG to ICO Favicon Converter - Convert a JPG or JPEG image into a favicon.ico file for browser tabs and website icons.