Best Free Online Developer Tools to Use in 2026
A practical, opinionated list of the best free online developer tools worth using in 2026, organized by category so you can find what you need fast.
Aug 08, 2026
Mu ("my") is a lowercase Greek alphabet letters used in formulas, constants, and academic notation. This HTML entity enables web developers to display this character reliably across all browsers without encoding issues.
U+03BC
μ
\03BC
Use this HTML entity in mathematical formulas and scientific constants. For example, π for pi, α for alpha, β for beta.
Mistake: Confusing μ (mu) with µ (micro sign)
Fix: The micro sign µ is technically a different character (U+00B5) from Greek mu μ (U+03BC), though they look identical. Use μ for Greek text and µ for measurements.
Mistake: Using u instead of μ in scientific notation
Fix: Use μ (mu) for micro- prefix in measurements like μm (micrometer). Writing "um" instead of "μm" is incorrect in scientific contexts.
Select any code to highlight it before copying.
| Unicode | U+03BC |
|---|---|
| Hex Code | μ |
| HTML Code | μ |
| HTML Entity | μ |
| CSS Code | \03BC |
| Windows Shortcut | |
| Mac Shortcut | |
Blog
A practical, opinionated list of the best free online developer tools worth using in 2026, organized by category so you can find what you need fast.
Aug 08, 2026
A practical decision guide to choosing the right hash algorithm: MD5, SHA-1, SHA-2, SHA-3, bcrypt, argon2, PBKDF2, and SRI, with comparisons and clear recommendations.
Aug 08, 2026
A thorough, practical comparison of hand-written CSS and Tailwind CSS: learning curve, maintainability, performance, team workflows, and when each approach wins.
Aug 08, 2026
Learn practical, step-by-step techniques to improve LCP, INP, and CLS on your website. A developer-focused guide with real measurements and fixes.
Aug 08, 2026
Learn practical, production-ready ways to use Base64 encoding: data URLs for images, JWT payloads, API tokens, and email attachments, with real code examples.
Aug 08, 2026
Learn how AES encryption works, the differences between AES-128, AES-192, and AES-256, and how to encrypt and decrypt data online.
Jun 23, 2026