Developer Tools
Developer tools and calculators for networking, text encoding, color conversion, hashing, regex testing, and system administration.
Networking, encoding, hashing, rate limits and outage cost. 8 tools for developers and system administrators. Algorithms and complexity sit under Computer Science.
IP subnet is the one people reach for most, and it rewards understanding rather than memorising. An IPv4 (Internet Protocol version 4) address is 32 bits split into a network part and a host part, and subnetting is nothing more than choosing where to make that cut. CIDR notation writes the cut as a slash and the number of network bits, so a /24 leaves 8 host bits, which is 256 addresses and 254 usable ones once the network and broadcast addresses are taken out. The dotted mask carries exactly the same information in a different shape.
Downtime cost estimates the direct revenue loss only, and the page says so plainly. Churn, engineering response at premium rates, support volume for weeks afterwards and reputational damage are all real, and none of them are in the number. Full cost typically runs two to five times the direct figure.
The hashing and encoding tools run entirely in your browser. Nothing you paste in leaves the page.
Luhn Algorithm Validator
Validate any credit card, IMEI, or ID number using the Luhn algorithm checksum. Identifies Visa, Mastercard, American Express, Discover, and Diners Club.
SHA-256 / MD5 Hash Generator
Generate MD5, SHA-1, SHA-256, and SHA-512 cryptographic hashes of any text. Useful for data integrity verification, checksums, and security analysis.
AI API Token Cost Calculator
Estimate AI API costs from token counts and the per-million rates you enter. Compare two models, split input against output, and project monthly spend.
API Rate Limit Calculator
Calculate API usage against rate limits to determine if your call volume fits within plan limits, and how to optimize request scheduling.
Server Downtime Cost Calculator
Calculate server downtime cost from hourly revenue, lost conversions, and support overhead. Returns cost per incident and annual risk exposure for SLA planning.
Bitwise Operations Calculator
Perform bitwise AND, OR, XOR, NOT, left shift, and right shift on integers. See results in binary, decimal, hexadecimal, and octal with step-by-step breakdown.
Text to Hexadecimal Converter
Convert text to hexadecimal and back using true UTF-8 byte encoding. Shows every code point, its bytes, and which characters need more than one.
IP Subnet Calculator
Calculate subnet mask, network address, broadcast address, and host range from any IP address and CIDR notation. Essential for network administrators.