All tools

Subnet, CIDR, IPv4/IPv6 and other network calculations for infrastructure engineers and sysadmins.

• Subnet Calculator (IPv4 CIDR) Enter an IP and CIDR to instantly get the netmask, network, broadcast, host range and total number of addresses.
• IPv6 Subnet Calculator Get the network, address range, total count and compressed/expanded form of any IPv6 prefix.
• CIDR ↔ IP Range Converter Expand a CIDR to its address range, or collapse an IP range into minimal CIDR blocks.

Hash, Base64, JWT, HMAC, URL encode/decode — an encoding & decoding toolkit for developers.

• Base64 Encode / Decode Convert text to Base64 and back, with full Unicode (UTF-8) support.
• URL Encode / Decode Percent-encode text for safe use in URLs, or decode %xx sequences back.
• Hash Generator (MD5, SHA-1, SHA-256, SHA-512) Compute MD5, SHA-1, SHA-256, SHA-384 and SHA-512 digests from any text.
• JWT Decoder & Validator Decode a JWT's header and payload, inspect its claims, and verify an HS256 signature.
• JWT Generator (HS256) Create and sign a JSON Web Token (HS256/384/512) from a payload and secret.
• HMAC Generator (SHA-1, SHA-256, SHA-512) Compute an HMAC from a message and secret key using SHA-1/256/384/512, as hex or Base64.
• Hex ↔ Text Converter Convert text to hexadecimal and decode hex back to text, with UTF-8 support.

Generate strong passwords, measure entropy, create API keys and manage password policies.

• Password Generator Create strong, random passwords with custom length and character sets — generated securely in your browser.
• Password Strength & Entropy Checker Measure a password's entropy in bits and estimate how long it would take to crack.
• API Key & Secret Generator Generate cryptographically secure API keys and secrets in hex, Base64url or alphanumeric.
• UUID Generator (v4 & v7) Generate random v4 UUIDs or time-ordered v7 UUIDs in bulk, ready to copy.
• Bcrypt Hash Generator & Checker Hash a password with bcrypt at an adjustable cost factor, or verify a password against a hash.
• .htpasswd Generator (bcrypt) Create a secure Apache/nginx basic-auth entry with a bcrypt-hashed password.

Estimate risk costs, GDPR fines and security ROI — calculators for managers and CISOs.

• Data Breach Cost Estimator Estimate the financial impact of a data breach from records exposed and per-record cost.
• GDPR Fine Calculator Estimate the maximum GDPR penalty from annual turnover and infringement tier.
• Ransomware Downtime Cost Calculator Estimate the total impact of a ransomware attack from downtime, recovery and ransom.
• Security ROI (ROSI) Calculator Compute the return on a security investment from expected loss and mitigation effectiveness.
• Password Policy Generator Turn your password rules into a written policy plus Linux PAM and Windows config.

Cron, JSON, YAML, regex, redirects — everyday utilities for DevOps and backend engineers.

• Cron Expression Explainer Decode any cron schedule into plain English and preview the next run times.
• JSON Formatter & Validator Beautify, minify and validate JSON with clear error messages.
• YAML ↔ JSON Converter Convert YAML to JSON and back, with clear parse errors.
• Regex Tester Test regular expressions against text and inspect every match and group.
• .htaccess & nginx Redirect Generator Turn a list of old → new URLs into Apache .htaccess and nginx redirect rules.
• Unix Timestamp Converter Convert Unix/epoch timestamps to human-readable dates and back — seconds or milliseconds.
• JSON ↔ CSV Converter Convert a JSON array of objects to CSV and back, with proper quoting and headers.
• Number Base Converter Convert between binary, octal, decimal and hexadecimal — with big-number support.