Service Introduction
Welcome to the CaYiHuo Free Subdomain Service! This service aims to provide free subdomains for individual developers, students, and anyone needing a testing environment.
Target Users
- Personal developers testing projects
- Students building learning environments
- Temporary project showcases
- API callback domains
Domain Format
Your subdomain format will be:
[your-choice].domains.cayihuo.top
Examples
myblog.domains.cayihuo.toptest123.domains.cayihuo.topapi-demo.domains.cayihuo.top
Application Rules
3.1 Eligibility
- ✅ No registration required
- ✅ 1 subdomain per user
- ✅ Instant activation after application
3.2 Naming Rules
| Rule | Description |
|---|---|
| Length | 3-20 characters |
| Characters | English lowercase letters (a-z) and numbers (0-9) only |
| Prohibited | Sensitive words, invalid words, duplicate domains |
| Format | All lowercase, no special symbols |
Naming Examples
✅ Valid: myblog, test123, api-v1
❌ Invalid: MyBlog (uppercase), test-123 (hyphen), my blog (space)
Usage Guidelines
4.1 DNS Configuration
After applying, you can configure the following record types:
| Record Type | Description | Example |
|---|---|---|
| A | IPv4 address | Point to server IP |
| AAAA | IPv6 address | Point to server IPv6 |
| CNAME | Domain alias | Point to another domain |
| TXT | Text record | Verify domain ownership |
| MX | Mail exchange | Mail server |
Multi-level domains supported: e.g. blog.yourname.domains.cayihuo.top
| Record Type | Host | Value |
|---|---|---|
| A | Your domain | Your server IP |
| CNAME | blog | Other domain |
Note: DNS changes typically take effect within minutes, up to 24 hours maximum. NS records are not supported.
4.2 Content Restrictions
The following content is prohibited on this service:
- 🚫 Illegal content
- 🚫 Pornography, gambling, phishing sites
- 🚫 Malicious attacks, phishing links
- 🚫 Spam email
- 🚫 Any content violating Chinese laws
Recycle Mechanism
5.1 Automatic Recycle
- 30 days of no access: If your domain has no visitors for 30 days, it will be automatically recycled
- Release after recycle: The domain will be released immediately and available for others to apply
5.2 Violation Recycle
Immediate recycle without notice if:
- Violating content is published
- Used for illegal purposes
- Used for malicious attacks
Terms of Service
- This service is provided free of charge
- This service provides no warranty including availability, data security, etc.
- We reserve the right to modify these rules at any time
- Using this service means you agree to all rules above
FAQ
Q1: DNS not working?
Please check:
- Is the A record configured correctly?
- Is the domain name correct (don't include domains.cayihuo.top)?
- DNS propagation takes a few minutes, please wait
Q2: Domain was recycled?
After recycling, you can reapply for a new domain (wait for the old domain to be fully released).
Q3: Can I point to GitHub Pages?
Yes! Just configure the A record to GitHub Pages' IP address.
Q4: Can I add CNAME records?
Yes! Supports A, AAAA, CNAME, TXT, MX records. NS records are not supported.
Contact the administrator if you have any questions.