/Tools

Things I built for myself

123 small utilities I use in my own workflow. No sign-up, no tracking — everything runs in your browser. Star the ones you reach for most; favorites are saved on this device.

Developer

41

Encoders, decoders, generators and converters for everyday coding.

Backslash Escape

Escape text for code strings.

escapestringcode

Base32 Encode / Decode

Text ↔ Base32.

base32encodedecode

Base64 ↔ Hex

Convert Base64 and hex both ways.

base64hexconvert

Base64 Encode / Decode

Text ↔ Base64, in your browser.

base64encodedecode

Basic Auth Header

Build a Basic Auth header.

Card / Luhn Validator

Validate numbers with the Luhn check.

luhncardchecksum

Chmod Calculator

Unix permissions ↔ octal & symbolic.

chmodpermissionsunix

Common Ports

What runs on which port?

portsnetworkreference

Cron Explainer

Decode cron expressions to plain English.

cronscheduleexplain

cURL to fetch

Convert curl commands to fetch().

File Hash

Checksum files in your browser.

hashchecksumfile

File Size Converter

Bytes ↔ KB/MB/GB & KiB/MiB/GiB.

bytessizeconvert

Hash Generator

SHA hashes, computed locally.

HMAC Generator

Sign messages with HMAC, locally.

HTML Entity Encoder

Encode & decode HTML entities.

htmlentitiesencode

HTML to JSX

Paste HTML, get JSX.

HTTP Status Codes

Look up any HTTP status code.

httpstatusreference

Image to Base64

Inline images as data URIs.

imagebase64data-uri

IPv4 Subnet Calculator

CIDR to network, mask & host range.

JSON → TypeScript

Generate TS interfaces from JSON.

jsontypescripttypes

JSON ↔ YAML

Convert config between JSON & YAML.

JSON Diff

Structural diff for JSON.

jsondiffcompare

JSON String Escape

Escape text into a JSON string.

jsonescapestring

JSON to Query String

JSON object to a query string.

JWT Decoder

Inspect a JWT, fully in your browser.

JWT Generator

Build & sign an HS256 JWT.

MAC Address Generator

Random MAC addresses on demand.

macnetworkgenerator

MIME Type Lookup

Extensions ↔ MIME types.

mimecontent-typereference

Number Base Converter

Binary, octal, decimal & hex.

Password Generator

Strong random passwords, generated locally.

passwordrandomsecurity

Query String Parser

Break a query string into params.

Random Number Generator

Secure random numbers in a range.

randomnumbergenerator

Regex Tester

Test regex with live match highlighting.

regexpatternmatch

Text ↔ Binary / Hex

Encode text as binary, hex or decimal.

Text Diff

Spot the difference between two texts.

diffcomparetext

Timestamp Converter

Unix epoch ↔ human dates.

unixtimestampdate

TOTP / 2FA Generator

Live 2FA codes from a secret.

ULID Generator

Sortable, unique ULIDs in bulk.

ulididgenerator

URL Encoder & Parser

Encode, decode & inspect URLs.

User Agent Parser

Decode a User-Agent string.

user-agentbrowserparse

UUID Generator

Bulk random UUID v4 generator.

uuididgenerator

Formatting

12

Clean up, validate and reshape structured data.

.env ↔ JSON

Convert .env files to JSON.

CSS Minifier

Minify CSS and see the savings.

cssminifyoptimize

CSV → Markdown Table

Turn CSV into a Markdown table.

csvmarkdowntable

CSV to JSON

CSV into a JSON array.

HTML to Text

Extract plain text from HTML.

JSON ↔ CSV

Convert between JSON arrays and CSV.

JSON Formatter

Beautify, minify & validate JSON.

jsonformatvalidate

JSON Key Sorter

Alphabetize JSON object keys.

JSON to XML

Turn JSON into indented XML.

Markdown → Slack

Paste Markdown, get Slack-ready text.

markdownslackformatting

Markdown Preview

Live Markdown to HTML preview.

markdownhtmlpreview

SQL Formatter

Tidy up SQL queries.

sqlformatbeautify

Text

20

Transform and inspect plain text.

Caesar / ROT13 Cipher

Shift-cipher text, including ROT13.

cipherrot13caesar

Case Converter

Switch between every naming case.

Character Frequency

Tally character & word frequency.

frequencycountanalyze

Fancy Text Generator

𝐁𝐨𝐥𝐝 & 𝓯𝓪𝓷𝓬𝔂 Unicode text.

unicodefancyfonts

Find & Replace

Search & replace, with regex.

findreplaceregex

Leetspeak Translator

Turn text into l33t.

Line Tools

Sort, dedupe & reorder lines.

linessortdedupe

Lorem Ipsum Generator

Placeholder text on demand.

loremplaceholderdummy

Morse Code Translator

Text ↔ Morse code.

morseencodedecode

NATO Phonetic Alphabet

Spell words with Alpha, Bravo, Charlie.

natophoneticspell

Pig Latin Translator

English to Pig Latin.

pig-latinfuntext

Remove Accents

Strip diacritics from text.

accentsdiacriticsunicode

Reverse Text

Reverse characters, words or lines.

reversetextflip

ROT47 Cipher

Rotate ASCII with ROT47.

rot47cipherencode

Slug Generator

Titles into URL-friendly slugs.

Text Repeater

Repeat text any number of times.

repeattextduplicate

Title Case Converter

Smart title-case for headings.

titlecasecapitalize

Unicode Inspector

Inspect every code point.

unicodecodepointutf-8

Whitespace Cleaner

Tidy up messy whitespace.

whitespacetrimclean

Word & Character Counter

Count words, chars & reading time.

Design

25

Colors, contrast and visual helpers.

Aspect Ratio Calculator

Keep dimensions in the right ratio.

aspectratiodimensions

Border Radius Generator

Design rounded corners visually.

cssborderradius

Box Shadow Generator

Design CSS shadows with live preview.

cssshadowpreview

Color Converter

HEX ↔ RGB ↔ HSL with preview.

Color Harmonies

Build a palette from one color.

colorpaletteharmony

Color Mixer

Mix two colors by ratio.

Color Name Finder

HEX to the closest color name.

Color Shades Generator

Tints & shades from one color.

colorshadespalette

Contrast Checker

WCAG contrast ratio checker.

contrastwcaga11y

CSS Clamp Generator

Fluid clamp() for responsive type.

cssclampresponsive

CSS Filter Playground

Compose CSS filters visually.

CSS Gradient Generator

Linear & radial gradients, copy CSS.

cssgradientpreview

CSS Grid Generator

Design CSS grid templates.

CSS Specificity

Score any CSS selector.

cssspecificityselector

CSS Triangle Generator

Pure-CSS triangles via borders.

csstriangleshape

Cubic Bezier Easing

Design CSS easing curves.

csseasinganimation

Flexbox Playground

Visualize flexbox properties.

cssflexboxlayout

Glassmorphism Generator

Frosted-glass CSS, live.

Golden Ratio Calculator

Divide a length by 1.618.

goldenratiolayout

Neumorphism Generator

Soft UI shadows, generated.

cssneumorphismshadow

Opacity to Hex

Opacity % to hex alpha.

opacityhexalpha

px ↔ rem Converter

Convert CSS px and rem units.

SVG to CSS

SVG to a CSS background data URI.

Text Gradient Generator

Gradient text in pure CSS.

cssgradienttext

Text Shadow Generator

Design CSS text shadows live.

Misc

25

Everything else.

Age Calculator

Exact age from a birth date.

agedatebirthday

Average & Stats

Mean, median, mode & more.

averagestatisticsmath

BMI Calculator

Work out Body Mass Index.

bmihealthcalculator

Coin Flip

Flip fair coins in bulk.

Compound Interest

Watch compounding add up.

interestfinancesavings

Date Difference

How far apart are two dates?

datedifferenceduration

Dice Roller

Roll dice with 2d6+3 notation.

Discount Calculator

Sale price and savings.

discountpricepercent

Duration Calculator

Time between two moments.

durationtimedifference

Factorial Calculator

Exact factorials, big integers.

factorialmathbigint

Fibonacci Generator

List the Fibonacci sequence.

fibonaccisequencemath

GCD & LCM Calculator

GCD and LCM of any numbers.

Loan Calculator

Monthly payment & total interest.

Number Properties

Primes, factors & more for a number.

primefactorsmath

Number to Words

Write numbers out in words.

numberwordsspell

Percentage Calculator

Everyday percentage maths.

percentmathcalculator

Permutations & Combinations

nPr and nCr, exactly.

combinatoricsmathfactorial

QR Code Generator

Make a QR code from text.

qrbarcodegenerator

Quadratic Solver

Solve any quadratic equation.

quadraticequationmath

Random Picker

Pick random items from a list.

randompickerchoice

Roman Numeral Converter

Numbers ↔ Roman numerals.

romannumberconvert

Scientific Notation

Decimal ↔ scientific notation.

scientificnumberconvert

Time Zone Converter

Compare a time across zones.

timezonetimeconvert

Tip Calculator

Tip and split the bill.

Unit Converter

Length, weight & temperature units.

unitsconvertmeasure