Practical guides for free online tools. 325 articles — page 12 of 28.
Your BMI says you're 'overweight.' Your body fat percentage is 15% and your waist-to-hip ratio is 0.85. The BMI number is useful — but incomplete. Here are the metrics that fill in the gaps.
QR codes in public places are increasingly being replaced with malicious stickers that redirect to phishing sites. A QR code scanner with a preview feature can save you from the attack.
Writing Markdown in a text editor and previewing it in a separate window is slow. A live Markdown preview that updates as you type catches formatting errors instantly. Here's the workflow.
A unit converter transforms miles to kilometers (physical measurement). A base converter transforms binary to hexadecimal (numerical representation). They are both 'converters' — but the math is unrelated.
GIF Search helps you find the perfect reaction GIF for a tweet. YouTube Thumbnail helps you preview how your video thumbnail will look on different devices. Different tools, different platforms, same creator.
You made 200 decisions today. The last one — 'What should I eat for dinner?' — feels impossible. A food picker eliminates the decision. Here's the neuroscience of why choosing food is disproportionately draining.
Google Translate and DeepL are free and handle 90% of casual translation needs. But the last 10% — legal documents, medical instructions, literary prose — still needs human judgment. Here's the boundary.
The average human reaction time to visual stimulus is 250 milliseconds. Pro gamers average 150-180ms. F1 drivers react in 100ms. Here's what reaction tests measure, how to improve, and where the biological limits are.
A random 12-character password is uncrackable but unmemorable. A 4-word passphrase is also uncrackable and you can actually remember it. Here's the math behind both methods.
Bing Wallpaper shows you a stunning landscape from somewhere on Earth. Pet Wallpaper shows you an adorable animal. Both are free, daily, and high-resolution. But they serve different moods.
A perpetual calendar can tell you the day of the week for any date — past or future. The math behind it is elegant, and the exceptions (like 2100 not being a leap year) reveal the genius of the Gregorian reform.
Your API uses snake_case. Your frontend uses camelCase. Your CSS uses kebab-case. Converting between them manually is error-prone. Here's a case converter that handles all four.