TOOLBOX

Tiny tools that save you time.

Calculators and converters that work instantly, right in your browser. No sign-up, no clutter, nothing to install.

What ToolBox is

ToolBox is a collection of 322 free, single-purpose web tools — calculators, converters, formatters, and generators, organised into 13 categories. Each one lives on its own page and does exactly one job: work out a percentage, convert a colour, format some JSON, generate a password, check a loan repayment.

Every tool runs entirely in your browser. The numbers, text, and files you work with are not uploaded or stored on a server, there is nothing to install, and nothing needs an account. It is built and maintained by one developer — see the about page for who and why.

New to a calculation? The guides explain the maths and formats behind the most-used tools in plain language — how the numbers are worked out, and where they stop being reliable.

Percentage Calculator

Calculate percentages, increases, and decreases instantly.

Age Calculator

Find exact age in years, months, and days from any birth date.

Unix Timestamp Converter

Convert between Unix time and human-readable dates.

BMI Calculator

Calculate Body Mass Index from height and weight, in metric or imperial.

Word & Character Counter

Count words, characters, sentences, and reading time as you type.

Password Generator

Generate strong, random passwords with custom length and character rules.

Tip Calculator

Split a bill and calculate the right tip in seconds.

Unit Converter

Convert length, weight, and temperature between common units.

Color Converter

Convert colors between HEX, RGB, and HSL with a live preview.

Text Case Converter

Convert text to UPPERCASE, lowercase, Title Case, camelCase, and more.

Loan / EMI Calculator

Calculate monthly loan payments and total interest.

Compound Interest Calculator

See how savings or investments grow with compound interest over time.

Random Number Generator

Generate random numbers in a range, with or without duplicates.

JSON Formatter & Validator

Format, validate, and minify JSON with clear error messages.

Base64 Encoder / Decoder

Encode text to Base64 or decode Base64 back to plain text.

Days Between Dates Calculator

Find the number of days, weeks, or months between two dates.

Countdown Timer

Count down live to any future date and time.

Hash Generator

Generate SHA-1, SHA-256, and SHA-512 hashes of any text.

Regex Tester

Test a regular expression against text and see every match highlighted.

UUID Generator

Generate random version 4 UUIDs, one or many at a time.

Currency Converter

Convert between two currencies using an exchange rate you enter.

QR Code Generator

Turn any text or URL into a downloadable, scannable QR code.

Mortgage Calculator

Estimate your monthly mortgage payment, including tax, insurance, and PMI.

Resistor Color Code Calculator

Decode 4, 5, and 6-band resistor color codes into resistance, tolerance, and temperature coefficient.

Calculator

A simple, fast four-function calculator for everyday math.

Math

Date & Time

Health

Text

Word & Character Counter

Count words, characters, sentences, and reading time as you type.

Text Case Converter

Convert text to UPPERCASE, lowercase, Title Case, camelCase, and more.

Lorem Ipsum Generator

Generate placeholder text by paragraphs, sentences, or words.

Readability Score Checker

Estimate how easy a piece of text is to read.

Text Reverser

Reverse text by character, word order, or line order.

Morse Code Translator

Translate text to Morse code, or Morse code back to text.

Social Media Character Counter

Check your text against X, Instagram, TikTok, and other platform limits.

Text to Speech Reader

Have any text read aloud using your browser's built-in voices.

Word Frequency Counter

See which words appear most often in a block of text.

Emoji Picker

Search hundreds of emoji by keyword and copy them with one click.

Palindrome Checker

Check whether a word, phrase, or number reads the same forwards and backwards.

Duplicate Line Remover

Remove duplicate lines from any list, keeping the first occurrence.

Speech to Text

Turn spoken words from your microphone into text, using your browser's built-in speech recognition.

Keyword Density Checker

See how often each word or phrase appears in your text, and its density.

NATO Phonetic Alphabet Converter

Spell out text using Alpha, Bravo, Charlie… the NATO alphabet.

Pig Latin Translator

Translate text into Pig Latin.

Acronym Generator

Turn a phrase into an acronym from its first letters.

Text to Handwriting

Turn typed text into a handwriting-style image on paper.

Fancy Text Generator

Turn plain text into 𝐛𝐨𝐥𝐝, 𝑖𝑡𝑎𝑙𝑖𝑐, script, bubble, and other Unicode styles.

Alphabetizer

Sort a list of words or lines into alphabetical order, with options to reverse and remove duplicates.

Binary Translator

Convert text to binary and binary back to text, plus decimal and hexadecimal.

Number to Words Converter

Spell out numbers in words, including a currency mode for writing cheques.

Text Repeater

Repeat a word, phrase, or line any number of times, with optional separators.

Remove Line Breaks

Strip or replace line breaks and blank lines from pasted text in one click.

Security

Password Generator

Generate strong, random passwords with custom length and character rules.

Hash Generator

Generate SHA-1, SHA-256, and SHA-512 hashes of any text.

Password Strength Checker

See how strong a password is and why, without it ever leaving your browser.

Text Encryption / Decryption

Encrypt or decrypt text with a passphrase, using AES-256-GCM.

File Checksum Verifier

Compute a file's SHA-1/256/512 checksum and check it against an expected value.

TOTP (2FA) Code Generator

Generate the same rotating codes as an authenticator app, from a Base32 secret.

Passphrase Generator

Generate a memorable, random word-based passphrase.

Credit Card Number Validator

Check a card number against the Luhn checksum and detect its card type.

HMAC Generator

Generate an HMAC signature for a message using a secret key.

Base32 Encoder / Decoder

Encode text to Base32 or decode Base32 back to plain text.

File Encryption / Decryption

Encrypt or decrypt any file with a passphrase, using AES-256-GCM.

IBAN Validator

Validate an IBAN's format and mod-97 checksum.

Email Validator

Check email address syntax and confirm the domain can receive mail.

Test Credit Card Number Generator

Generate Luhn-valid fake card numbers for testing, not real purchases.

Protect PDF

Add password protection (AES-256) to a PDF, right in your browser.

Unlock PDF

Remove password protection from a PDF you already have the password for.

Image Metadata (EXIF) Viewer & Remover

See a photo's hidden camera/GPS metadata, then strip it before sharing.

PDF Redaction Tool

Permanently black out sensitive parts of a PDF and flatten it.

IBAN Generator

Generate checksum-valid fake IBANs for testing, not real accounts.

Caesar Cipher Encoder

Encode and decode Caesar shift ciphers and ROT13, with a brute-force view of all 25 shifts.

Design

Color Converter

Convert colors between HEX, RGB, and HSL with a live preview.

Color Palette Generator

Generate complementary, analogous, and shade palettes from one color.

Aspect Ratio Calculator

Calculate a matching width or height for any aspect ratio.

QR Code Generator

Turn any text or URL into a downloadable, scannable QR code.

CSS Box Shadow Generator

Design a box shadow visually and copy the ready-to-use CSS.

Favicon Generator

Turn an image into a full set of standard favicon sizes, ready to download.

Image Color Palette Extractor

Pull the dominant colors out of any image, with copyable hex codes.

CSS Border Radius Generator

Design rounded corners visually and copy the ready-to-use CSS.

Image Resizer

Resize an image to exact dimensions or a percentage, right in your browser.

Placeholder Image Generator

Generate a solid-color placeholder image at any size, ready to download.

CSS Text Shadow Generator

Design a text shadow effect visually and copy the ready-to-use CSS.

Color Blindness Simulator

See how a color appears under different types of color vision deficiency.

Barcode Generator

Turn any text into a scannable Code 39 barcode, ready to download.

CSS Flexbox Generator

Build a flexbox layout visually and copy the ready-to-use CSS.

CSS Grid Generator

Build a CSS grid layout visually and copy the ready-to-use CSS.

CSS Glassmorphism Generator

Design a frosted-glass card effect visually and copy the CSS.

Meme Generator

Add top/bottom captions to an image and download it as a meme.

Image Format Converter

Convert an image between PNG, JPEG, and WebP in your browser.

Image Compressor

Shrink an image's file size with a live quality/size preview.

Image Tinifier

Compress a JPEG with mozjpeg — TinyPNG-level results, right in your browser.

QR Code Scanner

Decode a QR code from an uploaded image or your camera.

WiFi QR Code Generator

Generate a QR code that lets phones join a WiFi network by scanning.

vCard QR Code Generator

Generate a QR code that adds a contact card when scanned.

Merge PDF

Combine multiple PDF files into a single document, right in your browser.

Split PDF

Extract a page range from a PDF into a new document, right in your browser.

Compress PDF

Shrink a PDF's file size by rebuilding it with an optimized internal structure.

Word ↔ PDF Converter

Convert a Word document to PDF, or pull a PDF's text into a new Word document — in your browser.

Image to PDF

Combine one or more JPG/PNG images into a single PDF, right in your browser.

PDF to JPG

Turn each page of a PDF into a downloadable JPG image, right in your browser.

Rotate PDF

Rotate every page of a PDF 90, 180, or 270 degrees, right in your browser.

Watermark PDF

Stamp text onto every page of a PDF, right in your browser.

Signature Generator

Draw or type a signature and download it as a transparent PNG.

Image Watermark

Stamp text onto a photo or image and download the result, right in your browser.

Image Crop

Crop an image to a custom area or common aspect ratio, right in your browser.

Image to Text (OCR)

Extract text from a photo or scanned image, right in your browser.

Organize PDF

Delete and reorder the pages of a PDF, right in your browser.

Add Page Numbers to PDF

Stamp page numbers onto every page of a PDF, right in your browser.

PDF to Text

Extract the plain text from a PDF, right in your browser.

CSV ↔ Excel Converter

Convert between CSV and Excel (.xlsx) files, right in your browser.

Images to GIF

Combine multiple images into an animated GIF, right in your browser.

Video to GIF

Turn a clip of a video into a high-quality animated GIF, right in your browser.

Video Trimmer

Cut a video down to a specific start and end time, right in your browser.

Video Compressor

Shrink a video's file size by re-encoding it at a lower bitrate, right in your browser.

Audio Converter

Convert an audio file to MP3 or WAV, right in your browser.

Rotate & Flip Image

Rotate an image in 90° steps or flip it horizontally/vertically.

Word Cloud Generator

Turn any text into a word cloud sized by how often each word appears.

SVG to PNG Converter

Convert an SVG vector image to a PNG raster image at any size.

Barcode Scanner

Decode a barcode from an uploaded image or your camera.

HEIC to JPG Converter

Convert iPhone HEIC/HEIF photos to JPG, right in your browser.

Video to Audio Extractor

Pull the audio track out of a video and save it as MP3 or WAV.

GIF to MP4 Converter

Convert an animated GIF into a much smaller MP4 video.

Video Rotator & Flip

Rotate a video in 90° steps or flip it horizontally/vertically.

Audio Trimmer

Cut an audio file down to the start and end time you choose.

Screen Color Picker

Pick the exact color of any pixel on your screen.

Base64 to Image Converter

Decode a base64 string or data URL back into a downloadable image.

Duplicate Image Finder

Find identical or visually similar images among a batch you upload.

Background Remover

Automatically remove the background from a photo of a person.

Video Merger

Join two or more video clips into a single video.

Video Watermark

Stamp a text watermark onto every frame of a video.

Video Sprite Sheet Generator

Sample frames from a video into one grid image.

Audio Silence Remover

Automatically cut quiet/silent stretches out of an audio file.

Image Compare / Diff Tool

Compare two images with a slider or a pixel-level diff.

Contact Sheet / Image Grid Maker

Arrange a batch of images into one grid, in any order — add more anytime, sort by name/date/size, or drag rows to reorder.

SVG Optimizer

Shrink an SVG's file size — comments, metadata, precision.

Image Rounded Corners

Round an image's corners and export a transparent PNG.

Photo Filters

Apply Instagram-style filters to a photo — grayscale, sepia, and more.

CSS clamp() Calculator

Generate a fluid, responsive clamp() value for font-size or spacing.

PDF Bookmark / TOC Generator

Add a table of contents (bookmarks) to a PDF.

QR Code Batch Generator

Generate many QR codes at once from a list, one per line.

Video Thumbnail Grabber

Capture a single still frame from a video at any timestamp.

Video to WebP/APNG Converter

Convert a video clip into an animated WebP or APNG image.

Markdown to PDF

Convert Markdown directly into a paginated, downloadable PDF.

YouTube Thumbnail Downloader

Grab the full-resolution thumbnail image from any YouTube video URL.

Cubic Bezier Generator

Design a CSS easing curve by dragging its control points and copy the cubic-bezier() value.

Finance

Developer

JSON Formatter & Validator

Format, validate, and minify JSON with clear error messages.

Base64 Encoder / Decoder

Encode text to Base64 or decode Base64 back to plain text.

URL Encoder / Decoder

Percent-encode or decode text and URLs safely.

Number Base Converter

Convert numbers between binary, octal, decimal, and hexadecimal.

Markdown Previewer

Write Markdown and see the rendered HTML preview live.

Text Diff Checker

Compare two blocks of text and highlight what changed.

Slug Generator

Turn any title into a clean, URL-friendly slug.

Regex Tester

Test a regular expression against text and see every match highlighted.

UUID Generator

Generate random version 4 UUIDs, one or many at a time.

HTML Entity Encoder / Decoder

Escape text to safe HTML entities, or decode entities back to text.

JWT Decoder

Decode a JSON Web Token's header and payload without a server.

Cron Expression Explainer

Turn a cron schedule expression into a plain-English description.

CSS Gradient Generator

Build a linear gradient visually and copy the ready-to-use CSS.

Color Contrast Checker

Check whether a text and background color pair meets WCAG contrast rules.

CSS Unit Converter

Convert between px, em, rem, and pt for a given base font size.

URL Parser

Break a URL down into protocol, host, path, and query parameters.

HTTP Status Code Reference

Look up what any HTTP status code means.

Meta Tag Generator

Generate SEO and social-preview meta tags, with a live search-result preview.

Image to Base64 Converter

Convert an image file into a Base64 data URI for embedding in code.

JavaScript Minifier & Compressor

Shrink JavaScript for production using Terser, entirely in your browser.

CSS Minifier & Compressor

Shrink CSS for production using CSSO, entirely in your browser.

Screen Resolution & Device Info

See your screen resolution, viewport size, browser, and device details.

IP Subnet Calculator

Calculate network address, broadcast, and usable host range from a CIDR block.

cURL Command Generator

Build a properly quoted curl command from a method, URL, headers, and body.

YAML ↔ JSON Converter

Convert between YAML and JSON instantly, in either direction.

CSV ↔ JSON Converter

Convert between CSV and JSON, with correct handling of quoted fields.

SQL Formatter

Format and beautify SQL queries with consistent keywords and indentation.

HTML Formatter & Minifier

Beautify HTML with clean indentation, or minify it to a single line.

XML Formatter & Validator

Format, validate, and minify XML with clear error messages.

.gitignore Generator

Generate a .gitignore file for your stack — Node, Python, Java, and more.

robots.txt / sitemap.xml Generator

Generate a robots.txt crawler policy or a sitemap.xml from a list of URLs.

Fake / Mock Data Generator

Generate realistic placeholder names, emails, addresses, and more for testing.

Markdown Table Generator

Turn CSV or spreadsheet data into a ready-to-paste Markdown table.

JavaScript Formatter & Beautifier

Beautify minified or messy JavaScript with clean, consistent indentation.

Python Formatter

Clean up Python whitespace, tabs, and blank lines without touching logic.

Python Syntax Highlighter

Highlight Python code and copy it as colored HTML or plain text.

requirements.txt Generator

Generate a requirements.txt from Python import statements or a package list.

Python ↔ JSON Converter

Convert Python dict/list literals to JSON, and back.

Python String Escape / Unescape

Convert text to a Python string literal (or back), in any quote style.

Pip Install Command Generator

Build a pip install command with version pins, index URL, and common flags.

Python venv Command Builder

Generate the venv create/activate commands for your OS and shell.

Python Regex Tester

Test Python re-style regex patterns, including named groups, against text.

Python Docstring Generator

Generate a Google, NumPy, or reST-style docstring from a function signature.

Python Type Hint Generator

Add type hints to a Python function signature, inferred from default values.

XML ↔ JSON Converter

Convert XML to JSON, and back, with attributes and arrays handled.

JSON Diff Checker

Compare two JSON objects and see exactly what changed.

User Agent Parser

Break a browser user agent string into browser, OS, and device info.

SEO Meta Tag Comparer

Paste two page sources and see exactly what changed in meta tags, breadcrumbs, and other SEO data — built for site migrations.

CSV to HTML Table Generator

Paste CSV or spreadsheet data and get a ready-to-paste HTML table.

What Is My IP

Show your public IP address, approximate location, and network provider.

DNS Lookup Tool

Query a domain's A, AAAA, MX, TXT, NS, CNAME, SOA, and CAA records.

JSON to TypeScript Interface Generator

Turn a sample JSON object into TypeScript interfaces or type aliases.

MAC Address Generator

Generate random MAC addresses, or look up a MAC's vendor.

HTML to Markdown Converter

Convert HTML into clean Markdown, preserving structure and formatting.

.env File Generator

Clean up and validate a .env file — duplicates, invalid keys, quoting.

.htaccess Redirect Generator

Build Apache redirect rules — HTTPS, www, and custom URL redirects.

Nginx Config Generator

Build a static site or reverse proxy Nginx server block.

Docker Compose Generator

Build a docker-compose.yml from services, ports, env, and volumes.

JSON Schema Generator

Turn a sample JSON object into a JSON Schema (draft-07).

SQL Query Builder

Build a SELECT statement visually — columns, WHERE, order, limit.

Fake REST API Response Generator

Generate realistic fake JSON for mocking an API response.

Semantic Version Bumper & Comparator

Bump a semver version, or compare two to see which is newer.

Base64 File Encoder/Decoder

Convert any file to Base64, or decode Base64 back into a file.

Fake Name Generator

Generate a full fake identity — name, address, phone, and email — for testing and sign-up forms.

Discord Timestamp Generator

Turn a date and time into a Discord <t:…> timestamp tag that shows in each viewer's own time zone.

UTM Link Builder

Add campaign tracking parameters to a URL for Google Analytics and other tools.

Education

Fun

Productivity

Embedded

Resistor Color Code Calculator

Decode 4, 5, and 6-band resistor color codes into resistance, tolerance, and temperature coefficient.

Ohm's Law Calculator

Solve for voltage, current, or resistance — plus power — from any two known values.

LED Series Resistor Calculator

Find the current-limiting resistor needed to safely drive one or more LEDs.

Voltage Divider Calculator

Calculate output voltage from two resistors, or the R2 needed to hit a target voltage.

Battery Life Estimator

Estimate runtime for a battery-powered project from capacity and average current draw.

PWM Duty Cycle Calculator

Convert between PWM frequency/duty cycle and raw on-time/off-time pulse widths.

RC Time Constant Calculator

Calculate resistor-capacitor time constant, cutoff frequency, and charge-time milestones.

UART Baud Rate / Bit Timing Calculator

Compute UART bit time, frame time, throughput, and baud rate divisor error.

Microcontroller Pinout Reference

Searchable pin reference for Arduino Uno/Nano/Mega, ESP32, ESP8266, and STM32 Blue Pill.

Bit/Register Calculator

Set, clear, and toggle individual bits in an 8/16/32-bit register with live hex/binary output.

Capacitor Code Decoder

Decode 3-digit/letter capacitor markings like "104" or "4n7" into standard capacitance values.

Wire Gauge (AWG) Current Capacity Calculator

Pick a safe wire gauge for a given current draw, run length, and acceptable voltage drop.

PID Controller Simulator

Tune Kp, Ki, and Kd and watch the closed-loop step response redraw live on an animated chart.

Inductor Color Code Calculator

Decode the 4-band color code on an axial inductor into its inductance value.

Resistor Power (Wattage) Calculator

Calculate resistor power dissipation and get a suggested safe wattage rating.

Series/Parallel Resistor Calculator

Combine any number of resistor values in series or parallel.

Series/Parallel Capacitor Calculator

Combine any number of capacitor values in series or parallel.

555 Timer Frequency Calculator

Calculate astable frequency/duty cycle or monostable pulse width for a 555 timer.

Op-Amp Gain Calculator

Calculate inverting or non-inverting op-amp gain from feedback and input resistors.

CRC Checksum Calculator

Compute CRC-8, CRC-16, or CRC-32 checksums over text or hex bytes.

Zener Diode Regulator Calculator

Size the series resistor for a zener shunt voltage regulator.

Decibel (dB) Calculator

Convert between power/voltage ratios and decibels.

Crystal Oscillator Load Capacitance Calculator

Find crystal load capacitance from C1/C2, or matched C1/C2 from a target CL.

Arduino Sketch Formatter

Reformat a .ino sketch with clean, brace-based indentation.

Arduino Board Pinout Reference (Extended)

Pinouts for Leonardo/Micro, Due, Pro Mini, ATtiny85, ESP32-C3/S3.

Arduino map() Function Calculator

Compute map(value, fromLow, fromHigh, toLow, toHigh), truncation included.

Arduino Serial Baud/Timing Calculator

Estimate Serial transfer time and effective throughput at a given baud rate.

Arduino millis()/micros() Rollover Calculator

See exactly when millis() or micros() overflow, and check interval math.

Arduino Analog Read Voltage Calculator

Convert analogRead() raw values to voltage, or the reverse, for 10/12-bit ADCs.

Arduino Servo Pulse Width Calculator

Convert servo angle (0-180°) to pulse width in microseconds, and back.

Arduino Board Manager URL / arduino-cli Generator

Generate Boards Manager URLs or arduino-cli commands for ESP32, RP2040, and more.

Arduino Syntax Highlighter

Highlight Arduino/C++ code and copy it as colored HTML or plain text.

Arduino SRAM Usage Estimator

Estimate global-variable SRAM usage against your board's memory budget.

Device Tests

Common questions

Do the tools send my data anywhere?
No. Calculations and file processing happen in your browser. The one exception is the "What Is My IP" tool, which by design reads your connection details from the request — this is noted in the privacy policy.
Is ToolBox free?
Yes, all 322 tools are free with no account and no paywall. The site is supported by advertising and anonymised traffic analytics, both described in the privacy policy.
Do I need to install anything?
No. Every tool is a normal web page and works in any modern browser on desktop or mobile.
Can I use the results for official purposes?
The tools are provided for general information. Financial and health calculators in particular are estimates and not professional advice — check the notes on each tool's page.
Something is wrong or missing.
Email micro.info.all@gmail.com with a bug report or a tool request — it goes straight to the person who maintains the site.