Free utilities for building websites. More tools are added over time.
日本語版（セオツールズ）
Password generator
Generate strong passwords with letters, numbers, and symbols
Bcrypt hash
Hash text with Bcrypt
robots.txt generator
Build robots.txt allow/disallow rules
.htaccess redirects
Generate Apache redirects (HTTPS, www, migrations)
nslookup
Look up DNS records for a domain
Redirect checker
Trace redirect chains for a URL
Site status checker
Check HTTP status for a URL
IP address checker
Show your IP, forwarded headers, and user agent (with consent)
OGP checker
Fetch OGP and preview X, Facebook, and LINE-style cards
Tag duplicate checker
Detect duplicate meta tags and OGP
HTML size checker
Measure downloaded HTML byte size
Character count
Live character count and whitespace breakdown
English word count
Words, characters, lines, and paragraphs
Link Map Insights
Generate an internal link map in one click (WordPress plugin)