Free tools Windows power users keep installed
One-click scans. No signup required.
Some links on this page are affiliate links: if you buy through them we may earn a commission, at no extra cost to you.
To point app.example.com from Hostinger to an external server, add a DNS record at the provider that controls your domain’s authoritative nameservers. Use an A record for an IPv4 address, an AAAA record for an IPv6 address, or a CNAME for a hostname supplied by a managed service.
DNS is only one part of the setup. You must also configure the external server or platform to accept the subdomain and issue an HTTPS certificate for it.
What “pointing a subdomain” means
A subdomain can use different infrastructure from the root domain:
example.com → Existing Hostinger website
app.example.com → External application serverThis does not transfer your domain registration or move the entire website. It maps one hostname to another destination while the parent domain remains registered at Hostinger.
#1 Best Overall
- 40 Gbps 2000 Mhz High Speed: The Cat 8 ethernet cable support max. 40 Gbps data transfer and 2000 MHz Brandwith, ideal for gaming and streaming, greatly improving upload and download speed, sound, image and resolution quality
- Excellent Anti-interference: The ethernet cable comes with 4 shielded foiled twisted pairs (F/FTP), pure copper core and gold-plated RJ45 connector, reducing interference, noise and crosstalk, making network speed faster and more stable
- Marvelous Durability: Internet cable wrapped with quality cotton braided cord, which makes the LAN cable stronger and more durable. The test proves that this internet cable can be bent at least 10000 times without broken, very suitable for long-term use
- PoE Supported: All lengths of ethernet cord can support the PoE power supply function except 65ft. You don't need additional power supply when installing a PoE camera, which is very convenient and safe
- Wide Compatibility: With the RJ45 Connector, network cable can be perfectly compatible with computers, laptops, modems, routers, PS5, X-Box and other networking devices. It can also be fully backward compatible with Cat7, Cat6e, Cat6, Cat5e, Cat5
Keep these roles separate:
- Registrar: where the domain was purchased.
- DNS host: where the authoritative nameservers point and DNS records are managed.
- Web host: where the website or application runs.
Your domain may be registered at Hostinger while its DNS is hosted at Cloudflare or another provider. In that case, changing records in Hostinger will not affect public DNS.
1. Check where DNS is managed
In Hostinger, open hPanel → Domains → Manage → DNS / Nameservers. The exact labels can vary slightly by account and hPanel layout.
You can also check from a terminal:
dig NS example.com +shortOn Windows PowerShell or Command Prompt, use:
nslookup -type=NS example.comIf the results show Hostinger nameservers, use Hostinger’s DNS editor. If they show Cloudflare, Route 53, GoDaddy, Namecheap, or another provider, create the record there instead. Hostinger documents this limitation in its DNS zone editor guidance.
2. Choose the correct DNS record
| What the external provider gives you | Record | Use |
|---|---|---|
| Public IPv4 address | A |
Maps the hostname to IPv4 |
| Public IPv6 address | AAAA |
Maps the hostname to IPv6 |
Hostname such as customer.vendor.com |
CNAME |
Aliases the subdomain to another hostname |
Use the record type required by the external provider. Do not use a CNAME for an IP address, and do not add both a CNAME and an A record for the same hostname.
3. Point the subdomain to an IPv4 server with an A record
Use this method when the external server provides a fixed public IPv4 address.
In Hostinger, open the DNS records editor and add a record with these values:
| Field | Example |
|---|---|
| Type | A |
| Host/Name | app |
| Points to/Content | 203.0.113.10 |
| TTL | Default |
For app.example.com, the Host field normally contains only app, not the complete domain name. Hostinger’s external subdomain instructions and A-record documentation use this label-based format.
The Tool Desk
Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →Outbyte PC Repair FREERepair Windows errors before they cause bigger problemsFix Now →Rank #2
- Cat 6 performance at a Cat5e price but with higher bandwidth
- High Performance Cat6, 30 AWG, RJ45 Ethernet Patch Cable provides universal connectivity for LAN network components such as PCs,computer servers,printers,routers,switch boxes,network media players,NAS,VoIP phones
- Jadaol cat6 standard cable support Cat8 and Cat7 network and provides performance of up to 250 MHz 10Gbps and is suitable for 10BASE-T, 100BASE-TX (Fast Ethernet), 1000BASE-T/1000BASE-TX (Gigabit Ethernet) and 10GBASE-T (10-Gigabit Ethernet)
- UTP(Unshielded Twisted Pair) patch cable with RJ45 gold-plated Connectors and are made of 100% bare copper wire, ensure minimal noise and interference
- The unique flat cable shape allows for a cleaner and safer installation. You can easily and seamlessly make the cable run along walls, follow edges & corners or even make it completely invisible by sliding it under a carpet.
If the server also has a genuinely reachable public IPv6 address, add a separate record:
Type: AAAA
Host: app
Points to: 2001:db8::10
TTL: DefaultDo not add an AAAA record for an internal, broken, or unusable IPv6 address. Some visitors may prefer IPv6 and fail even though IPv4 works.
4. Point the subdomain to a managed service with a CNAME
Use a CNAME when the provider gives you a hostname rather than an IP address:
| Field | Example |
|---|---|
| Type | CNAME |
| Host/Name | app |
| Points to/Target | customer.vendor-example.com |
| TTL | Default |
A CNAME is often suitable for managed platforms because the provider can change its underlying IP addresses without asking you to update DNS. Enter the target exactly as supplied. Some providers also require a separate TXT or CNAME verification record.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
A CNAME generally cannot coexist with an A, AAAA, or other ordinary record at the same hostname. Before creating one, inspect the existing records for app and remove or update only the record that represents the old destination.
Do not confuse DNS with server configuration
Adding the DNS record does not create website files, open firewall ports, configure a web server, or register the custom domain with a SaaS platform.
On the external side, you may need to:
- Add
app.example.comin a custom-domain dashboard. - Configure a VPS control panel, reverse proxy, virtual host, or container.
- Set the web server hostname, such as Nginx
server_nameor ApacheServerName. - Set the application’s allowed host, public URL, callback URL, or CORS settings.
- Allow inbound ports 80 and 443 through cloud security groups, UFW, firewalld, or another firewall.
If DNS resolves but you see a default page, 404, 403, “unknown host,” or the wrong application, the external server usually has not been configured for the hostname.
Rank #3
- Designed for Outdoor & Direct Burial Installations – Heavy-duty double-shielded Cat8 Ethernet cable minimizes EMI/RFI interference and delivers stable long-distance performance. Waterproof, anti-corrosion PVC jacket allows safe direct burial and reliable use in outdoor or indoor environments.
- 26AWG for Stable High-Load Networks – Thicker 26AWG conductors provide faster, more stable data transmission than standard 32AWG cables. Ideal for high-performance home networks, gaming setups, smart homes, and data-intensive applications.
- F/FTP Shielding & Hyper-Speed Performance: Cat8 Ethernet cable constructed with 4 shielded foiled twisted pairs and 26AWG OFC conductors; supports bandwidth up to 2000 MHz and data transmission speeds up to 40 Gbps, effectively reducing signal interference and ensuring stable connections. Ideal for low-latency gaming, 4K/8K streaming, and high-speed internet connections.
- RJ45 Connectors & Wide Compatibility: Cat8 Ethernet cable with two shielded RJ45 connectors; compatible with networking switches, IP cameras, routers, Nintendo Switch, modems, PS3, PS4, Xbox, patch panels, servers, smart TVs, and more; works with Cat7, Cat6, Cat5e, and Cat5 devices
- Weatherproof & UV Resistant: Outdoor-rated Cat8 Ethernet cable with UV-resistant PVC jacket; withstands direct sunlight, extreme cold, humidity, and hot weather; anti-aging and durable; Includes 18-month support.
Cloudflare describes the same requirement in its subdomain DNS documentation: the hosting provider must be able to serve content for the hostname.
Outdated Drivers Are Slowing You Down
One free scan finds every outdated or missing driver and matches the right update for your exact hardware.Free scan · exact hardware matchWindows Errors? Fix Them Before They Spread
Repair common Windows errors and clear accumulated junk for a smoother, more stable PC - no reinstall needed.Free scan · no reinstallConfigure HTTPS separately
DNS never supplies an SSL/TLS certificate. After DNS works, configure HTTPS for the exact hostname:
https://app.example.com- External server: install a certificate covering
app.example.comand configure HTTPS on port 443. - Managed platform: add the custom domain in its dashboard and complete any requested verification. The platform may issue the certificate automatically.
- Cloudflare proxy: Cloudflare may provide the visitor-facing certificate when the record is proxied, but the origin still needs compatible TLS settings.
A certificate for example.com does not automatically cover every subdomain. A wildcard certificate such as *.example.com covers first-level names like app.example.com, but not v2.app.example.com.
If certificate issuance fails, check whether a CAA record restricts which certificate authorities may issue certificates.
Verify the setup in stages
Check authoritative DNS
dig NS example.com +shortCheck the subdomain record
dig A app.example.com
dig AAAA app.example.com
dig CNAME app.example.com
dig +trace app.example.comFor a public-resolver comparison:
dig @1.1.1.1 app.example.com
dig @8.8.8.8 app.example.comOn Windows:
nslookup app.example.com 1.1.1.1
nslookup app.example.com 8.8.8.8An A-record response should contain the external IPv4 address. A CNAME response should contain the provider’s hostname.
Quick wins for a faster PC:
Clear out junk files and repair common Windows errorsFree Scan →Scan for outdated or missing drivers - takes under a minuteDriver Scan →Test HTTP and HTTPS
curl -I http://app.example.com
curl -I https://app.example.comTo test the external server before DNS has fully propagated, force the hostname to a chosen IP:
curl -I --resolve app.example.com:443:203.0.113.10 https://app.example.com/This helps distinguish DNS problems from server-routing and certificate problems.
Rank #4
- High-Performance Connectivity: This Cat 6 ethernet cable is designed for superior performance, with a 24 AWG copper wire core. It provides universal connectivity as an ethernet cord for LAN network components such as PCs, servers, printers, routers, and more, ensuring reliable and fast network connections
- Advanced Cat6 Technology: Experience Cat6 performance with higher bandwidth at a Cat5e price. This network cable is future-proof, ready for 10-Gigabit Ethernet and backwards compatible with any existing Cat 5 cable network. It meets or exceeds Category 6 performance according to the TIA/EIA 568-C.2 standard
- Reliable Wired Network Solution: Known variously as a Cat6 network cable, ethernet cable Cat 6, or Cat 6 data/LAN cable, this RJ45 cable offers a more secure and reliable connection than wireless networks. It's ideal for internet connections that demand consistency and security
- Durable and Secure Design: The connectors of this ethernet cable feature gold-plated contacts and strain-relief boots for enhanced durability. Bare copper conductors not only improve cable performance but also comply with communication cable specifications
- High-Speed Data Transfer: With up to 550 MHz bandwidth, this ethernet cord is ideal for server applications, cloud computing, video surveillance, and streaming high-definition video. It also supports Power over Ethernet (PoE, PoE+, PoE++) for powering devices like IP cameras, VoIP phones, and wireless access points, ensuring fast and reliable network performance.
Test the application
Confirm that the correct application responds, API routes work, redirects use the intended hostname, cookies are scoped correctly, and callback or CORS settings do not still reference the old URL.
Propagation, caching, and timing
Hostinger says DNS updates can take up to 24 hours to apply globally, although many changes become visible sooner. The actual timing depends on the previous record’s TTL, resolver caching, browser behavior, and any CDN or application cache.
Recommended Free Tools
Do not repeatedly change the record while waiting. First check the authoritative answer, then compare public resolvers. Different networks may temporarily return the old destination.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.Troubleshooting by symptom
Nothing resolves
- Confirm that the domain uses Hostinger nameservers before editing Hostinger.
- Check that you edited the correct domain and used the correct label.
- Look for an old conflicting record.
- Compare the authoritative response with public resolvers.
The subdomain shows the wrong website
DNS is probably reaching the server, but the server is returning its default virtual host. Add the hostname to the external platform and configure the web server or reverse proxy to route app.example.com to the correct application.
HTTPS shows a certificate warning
Check certificate coverage, certificate issuance, port 443, firewall rules, reverse-proxy settings, and Cloudflare’s encryption mode. A DNS record alone cannot fix a certificate mismatch.
Hostinger rejects the CNAME
Look for an existing A, AAAA, or CNAME record with the same Host value. Remove only the conflicting record for that subdomain. Also verify that you are creating the CNAME for a subdomain rather than the root domain and that the target is a hostname, not an IP address.
Some users still see the old destination
This is usually resolver or browser caching. Check several resolvers, wait for the previous TTL to expire, and avoid making additional changes unless the authoritative record is incorrect.
Best Value
- 40 Gbps 2000 Mhz High Speed: The Cat 8 ethernet cable support max. 40 Gbps data transfer and 2000 MHz Brandwith, ideal for gaming and streaming, greatly improving upload and download speed, sound, image and resolution quality
- Excellent Anti-interference: The ethernet cable comes with 4 shielded foiled twisted pairs (F/FTP), pure copper core and gold-plated RJ45 connector, reducing interference, noise and crosstalk, making network speed faster and more stable
- Marvelous Durability: Internet cable wrapped with quality cotton braided cord, which makes the LAN cable stronger and more durable. The test proves that this internet cable can be bent at least 10000 times without broken, very suitable for long-term use
- PoE Supported: All lengths of ethernet cord can support the PoE power supply function except 65ft. You don't need additional power supply when installing a PoE camera, which is very convenient and safe
- Wide Compatibility: With the RJ45 Connector, network cable can be perfectly compatible with computers, laptops, modems, routers, PS5, X-Box and other networking devices. It can also be fully backward compatible with Cat7, Cat6e, Cat6, Cat5e, Cat5
HTTP works but HTTPS does not
DNS is likely working. Focus on the certificate, HTTPS listener, port 443 firewall rule, reverse proxy, redirects, Cloudflare encryption mode, and origin certificate hostname.
Important edge cases
External nameservers
If the setup is:
Registrar: Hostinger
DNS provider: Cloudflare
Server: External VPSKeep the domain registered at Hostinger, but create the record in Cloudflare. Do not move nameservers merely to point one subdomain externally.
Cloudflare proxying
Cloudflare records can be DNS-only or proxied. DNS-only exposes the origin address and leaves HTTPS to the origin. Proxied web traffic passes through Cloudflare, which can provide visitor-facing TLS and other edge features. Cloudflare notes that only compatible A, AAAA, and CNAME records can be proxied; MX and TXT records remain DNS-only. See its proxy-status documentation.
Proxying may be unsuitable for non-HTTP services, providers that prohibit reverse proxies, or applications that do not handle forwarded client-IP headers correctly.
Dynamic IP addresses
If the external public IP changes frequently, an A record will become stale. Use a dynamic DNS updater, a provider-issued CNAME, a tunnel, a reverse proxy, or a static IP plan.
Subdomain DNS delegation
An NS record can delegate an entire child zone such as app.example.com to another DNS provider, but that is unnecessary for simply pointing one hostname to a server. Use ordinary A, AAAA, or CNAME records unless the external provider specifically requires delegation. Cloudflare documents this advanced model in its subdomain delegation guide.
Email safety
Changing an app record should not normally affect email. Do not delete unrelated MX, SPF, DKIM, or DMARC records. If you change the domain’s nameservers instead of adding one subdomain record, recreate all required DNS records—including email records—at the new provider.
Do these 3 things before closing this tab:
1Clear out junk files and repair common Windows errors2Scan for outdated or missing drivers - takes under a minute3Repair Windows errors before they cause bigger problemsQuick Recap
Final checklist
- Confirmed which provider’s nameservers are authoritative.
- Chosen A, AAAA, or CNAME based on the supplied destination.
- Used only the subdomain label, such as
app, in the Host field. - Removed any conflicting record for that exact label.
- Added the custom hostname at the external provider.
- Configured server routing, application settings, and required ports.
- Issued a certificate for the exact subdomain.
- Verified DNS with more than one resolver.
- Tested HTTP, HTTPS, and the application itself.
- Left MX, SPF, DKIM, and DMARC records untouched.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
