Browse by task
Topics
Choose the area that matches what you are trying to do: calculate a bill, understand a color format, compare text, format data, or create a stronger password.
Calculators
Simple guides for percentages, ratios, ages, salaries, random numbers, and everyday math.
Guide
How to convert annual salary to hourly pay
Learn the simple salary-to-hourly formula, common assumptions, and examples for 40-hour weeks, part-time schedules, and unpaid time off.
Guide
How to calculate a percentage: the simple formula
Learn the basic percentage formula with simple examples for discounts, test scores, money, and everyday numbers.
Guide
Percentage increase vs percentage decrease explained
Understand percentage increase and percentage decrease with clear formulas, examples, and common mistakes to avoid.
Useful tools
calculators
Tip Calculator
Calculate tips, totals, and bill splits quickly.
calculators
Aspect Ratio Calculator
Calculate missing width, height, and ratios for images and video.
calculators
BMI Calculator
Calculate body mass index from height and weight.
calculators
Random Number Generator
Generate random numbers within a chosen range.
Tipping & bill splitting
Simple guides for tips, totals, and splitting shared bills.
Guide
Tipping around the world: a practical country guide
A practical guide to tipping customs around the world, with restaurant ranges, local expectations, and links to country-specific guides.
Guide
Tipping in Australia: when it is optional and when it makes sense
A clear guide to tipping in Australia, including restaurants, cafes, fine dining, service charges, and why tips are usually optional.
Guide
Tipping in Canada: how much to leave at restaurants
A simple guide to tipping in Canada, including restaurant ranges, tax, card prompts, service charges, and bill splitting.
Useful tools
calculators
Tip Calculator
Calculate tips, totals, and bill splits quickly.
calculators
Aspect Ratio Calculator
Calculate missing width, height, and ratios for images and video.
calculators
BMI Calculator
Calculate body mass index from height and weight.
calculators
Random Number Generator
Generate random numbers within a chosen range.
Color tools
Practical explanations of web color formats, contrast, and converters.
Guide
How to convert hex to RGB for CSS
Step-by-step guide to converting hex color codes to RGB for CSS, including the math, 3-digit shorthand, the modern rgb() syntax, and adding alpha transparency.
Guide
WCAG AA vs AAA contrast: what is the difference?
Understand WCAG AA and AAA color contrast levels, what ratios they use, and which target is realistic for most websites.
Guide
What is color contrast and why does it matter for accessibility?
Learn what color contrast means, why it affects readability, and how to check whether text and UI colors are easy to see.
Useful tools
Developer utilities
Small browser utilities for JSON, Base64, diffs, timestamps, URLs, UUIDs, and text work.
Guide
How to convert a Unix timestamp to a date
A plain-English guide to converting Unix (epoch) timestamps to readable dates, handling seconds vs milliseconds, and going back from a date to a timestamp.
Guide
What is a diff checker and when should you use one?
Learn what a diff checker does, how to compare two blocks of text online, how to read additions and deletions, and when a diff beats manual review.
Guide
Is it safe to paste JSON into an online formatter?
Learn when it is safe to use an online JSON formatter, what data you should avoid pasting, and a simple privacy checklist.
Useful tools
developer tools
Diff Checker
Compare two blocks of text and highlight differences.
developer tools
JSON Formatter
Format, validate, and minify JSON in the browser.
developer tools
Base64 Encoder / Decoder
Encode and decode Base64 text, including URL-safe Base64.
developer tools
UUID Generator
Generate UUIDs for development, testing, databases, and prototypes.
Writing & content
Simple guides for word counts, character limits, placeholder copy, reading time, and publishing drafts.
Guide
How many words fit in a 5-minute speech?
A practical guide to estimating 5-minute speech length, speaking pace, rehearsal time, and how many words to write.
Guide
Word count vs character count: what is the difference?
Understand the difference between word count and character count, when each one matters, and how to check both before you publish.
Useful tools
Password security
Plain-English guidance for stronger passwords and safer online habits.
Music practice
Beginner-friendly guides for tempo, timing, metronomes, stopwatches, and focused practice.
Guide
Best rhythm training apps for musicians: comparison for students
A researched comparison of rhythm-reading and rhythm-training apps, including prices, strengths, limitations, and a free browser option for beginners.
Guide
How to practice rhythm without an instrument
Learn how to improve rhythm away from your instrument using clapping, counting, tapping, rests, a metronome, and short reading exercises.
Guide
Rhythm reading for beginners: a mini-course on what to learn first
A step-by-step rhythm reading mini-course for beginners: pulse, quarter notes, rests, eighth notes, simple patterns, and practice levels.
Useful tools
music practice
Online Stopwatch
Use a simple online stopwatch for timing practice, study, workouts, or tasks.
music practice
Online Metronome
Practice with an online metronome and adjustable BPM.
music practice
Online Tuner
Tune instruments in the browser with a simple chromatic tuner.
music practice
Rhythm Trainer
Practice reading rhythms with generated exercises in the browser.
Images & graphics
Practical guides for optimizing, cropping, resizing, and converting images for fast, good-looking websites.
Guide
What is the best image size for a website hero banner?
How to size a website hero or banner image: the right width, aspect ratio, and file-size budget to look sharp and load fast — plus a free tool to make it.
Guide
How to compress images for the web without losing quality
Learn how image compression works, how to find the quality sweet spot, and how to shrink photos for the web without visible quality loss — for free.
Guide
How to make a square profile picture for free
A beginner's guide to cropping any photo into a perfect square profile picture or avatar — the right size, centering tips, and a free browser tool.
Useful tools
image tools
Image Optimizer
Crop, resize and compress images for the web with live file-size preview, all in the browser.
image tools
Compress Image for Web
Reduce image file size for faster pages without uploading anything.
image tools
Crop Image to Square
Crop any photo to a perfect 1:1 square for avatars and profile pictures.
image tools
Resize Image Online
Resize an image by max width in the browser, downscaling only.
Audio & sound
Practical guides for compressing, converting, and trimming audio so it sounds good and loads fast on the web.
Guide
How to compress audio for the web without losing quality
Learn how to compress audio for the web without wrecking the sound: bitrate, mono vs stereo, and a free in-browser tool to shrink files fast.
Guide
How to convert WAV to MP3 for free
How to convert WAV to MP3 for free in your browser — no upload, no install. Pick a bitrate, shrink the file by up to 95%, and download.
Guide
How to make an audio file smaller for email
How to make an audio file smaller for email and uploads: lower the bitrate, switch to mono, and trim — all free and private in your browser.
Useful tools
audio tools
Audio Optimizer
Trim, compress and convert audio to MP3 or WAV with a waveform editor, all in the browser.
audio tools
Compress Audio for Web
Reduce audio file size by lowering the bitrate and switching to mono, with a live size estimate.
audio tools
Convert WAV to MP3
Convert WAV files to MP3 in the browser and shrink them by up to 95%.
audio tools
Convert Audio to MP3
Convert WAV, M4A, OGG or FLAC to a universally-playable MP3.