A collection of online utilities to help you work efficiently.
77 Articles
Learn what TCP/UDP ports are, the most common port numbers and their services, how to interpret port scan results, and how to check open ports on any server for free online.
Learn how SPF, DKIM, and DMARC email authentication protocols work, how to configure them correctly, and how to use free online tools to verify your domain's email setup and improve deliverability.
Learn how binary, octal, decimal, and hexadecimal number systems work, how to convert between them, and their practical uses in programming and computer science.
Learn the naming conventions used in programming โ camelCase, snake_case, PascalCase, kebab-case โ when each is used, and how to convert between them instantly online for free.
Learn how URL encoding (percent-encoding) works, which characters must be encoded, the difference between encodeURI and encodeURIComponent, and how to encode or decode URLs online for free.
Learn how TOTP (Time-based One-Time Password) works, why it's more secure than SMS codes, and how to test your 2FA implementation with a free online TOTP generator.
Learn the difference between barcode formats (Code 128, EAN-13, UPC-A, QR Code), how to choose the right one, and how to generate printable barcodes online for free.
Learn how to split a GIF into individual frames online, understand GIF frame delay and structure, and download extracted frames as PNG files โ free, no upload.
Learn how checksums and CRC work, when to use MD5 vs SHA-256 vs CRC32, and how to verify file integrity online for free to detect corruption or tampering.
Learn what drives exchange rates, how to find the best rates for travel and transfers, and convert any currency pair instantly with a free online exchange rate calculator.