The Tool Desk
Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →Outbyte Driver Updater FREEScan for outdated or missing drivers - takes under a minuteDriver Scan →If example.com works but www.example.com fails, the two hostnames are not automatically connected. www is a separate subdomain that needs its own DNS record, an explicit mapping at your hosting platform, and (for HTTPS) a certificate covering that exact name. Fix those layers in that order, then redirect one hostname to the other as your canonical address.
Need a server to try this on? Antihost offers Linux VPS plans with NVMe storage, full root access and a 14-day free trial.
What is actually failing when www does not work?
Apex and www addresses look related to a person, but the internet treats them as different hostnames. In example.com, example.com is the apex (or root) domain. In www.example.com, www is a subdomain label. It does not automatically inherit a web destination from the apex.
As an Amazon Associate I earn from qualifying purchases.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
For a www visit to succeed, several independent layers must agree:
- DNS: the authoritative DNS zone must contain a usable record for
www.example.com. - Hosting configuration: the web server, application, or hosting platform must recognize
www.example.comas a hostname for your site. - Canonical redirect: if you prefer one address, both names must work first so the non-preferred one can redirect to the preferred one.
- TLS certificate: an HTTPS certificate must include the exact hostname the browser visits.
Cloudflare’s subdomain documentation summarizes the DNS requirement: a corresponding A, AAAA, or CNAME record should be created for a subdomain such as www, and the hosting provider must be able to serve that hostname. A www record can deliver the same content as the apex or act as the source of a redirect.
#1 Best Overall
- DUAL-BAND WIFI 6 ROUTER: Wi-Fi 6(802.11ax) technology achieves faster speeds, greater capacity and reduced network congestion compared to the previous gen. All WiFi routers require a separate modem. Dual-Band WiFi routers do not support the 6 GHz band.
- AX1800: Enjoy smoother and more stable streaming, gaming, downloading with 1.8 Gbps total bandwidth (up to 1200 Mbps on 5 GHz and up to 574 Mbps on 2.4 GHz). Performance varies by conditions, distance to devices, and obstacles such as walls.
- CONNECT MORE DEVICES: Wi-Fi 6 technology communicates more data to more devices simultaneously using revolutionary OFDMA technology
- EXTENSIVE COVERAGE: Achieve the strong, reliable WiFi coverage with Archer AX1800 as it focuses signal strength to your devices far away using Beamforming technology, 4 high-gain antennas and an advanced front-end module (FEM) chipset
- OUR CYBERSECURITY COMMITMENT: TP-Link is a signatory of the U.S. Cybersecurity and Infrastructure Security Agency’s (CISA) Secure-by-Design pledge. This device is designed, built, and maintained, with advanced security as a core requirement.
Cloudflare also notes that a subdomain record helps ensure that visitors who type www. before the domain can still find the website or application. Without that record, a browser may report DNS_PROBE_FINISHED_NXDOMAIN before any web server is contacted.
Fix www in the correct order
Do these steps in sequence. Changing a redirect or certificate before DNS works makes the diagnosis harder.
-
Find the authoritative DNS provider
Look up the domain’s active nameservers at the registrar or with a DNS lookup tool. The company where you bought the domain is not necessarily the company serving its DNS zone. Edit records at the provider named by the active nameservers. If you change records at an inactive DNS dashboard, nothing on the public internet changes.
-
Inspect and clean up the www record
Open the authoritative zone and search for every record whose name is
www. Remove stale or conflicting entries before adding the record required by your host. A hostname normally uses one of these choices:- A: points
wwwdirectly to an IPv4 address supplied by the host. - AAAA: points it to an IPv6 address supplied by the host.
- CNAME: points it to a hostname supplied by the hosting platform.
Do not copy an IP address from an unrelated service or guess a target hostname. Use the exact value shown in your hosting provider’s domain-mapping instructions. If an old CNAME, A, or AAAA record remains alongside a new, incompatible setup, resolvers can receive inconsistent answers.
- A: points
-
Add www to the hosting platform
In the host’s dashboard, add
www.example.comas an accepted, custom, mapped, or additional hostname. On a server you manage yourself, add the name to the web server’s virtual-host configuration and to the application’s allowed-host list, if it has one. DNS only directs traffic; it does not tell the origin which site to serve for that hostname.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 problemsSpecial offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy.Rank #2
Sale
TP-Link AC1200 WiFi Router Dual Band Wireless Internet Router (Archer A54) | 4 x 10/100 Mbps Fast Ethernet Ports, EasyMesh Compatible, Support Guest WiFi, Access Point Mode, IPv6 & Parental Controls- Dual-band Wi-Fi with 5 GHz speeds up to 867 Mbps and 2.4 GHz speeds up to 300 Mbps, delivering 1200 Mbps of total bandwidth¹. Dual-band routers do not support 6 GHz. Performance varies by conditions, distance to devices, and obstacles such as walls.
- Covers up to 1,000 sq. ft. with four external antennas for stable wireless connections and optimal coverage.
- Supports IGMP Proxy/Snooping, Bridge and Tag VLAN to optimize IPTV streaming
- Access Point Mode - Supports AP Mode to transform your wired connection into wireless network, an ideal wireless router for home
- Advanced Security with WPA3 - The latest Wi-Fi security protocol, WPA3, brings new capabilities to improve cybersecurity in personal networks
A DNS record can therefore resolve correctly while the browser receives a 404, 401, default server page, or another customer’s site. Those are host-mapping problems, not DNS failures.
-
Make both names resolve before redirecting
Choose whether the apex or www address will be canonical. First verify that both names reach your site. Then configure one permanent redirect to the preferred address. Put the redirect in one deliberate layer—origin, CDN, or application—and make the destination use the same scheme and hostname everywhere. A redirect cannot rescue a source hostname that does not resolve.
-
Enable HTTPS for the exact hostname
The certificate presented during an HTTPS connection must contain
www.example.comin its subject alternative names (SANs), or otherwise cover that exact name. A certificate valid only forexample.comdoes not automatically makewww.example.comvalid. Google’s certificate troubleshooting guidance uses this exact mismatch as an example: when a user visits www but the certificate covers only the apex, the browser reports a name error.Request or activate a certificate that includes every hostname you intend to serve. If both apex and www are reachable, include both as alternative DNS names. Install or activate the certificate at the layer that terminates TLS: your origin for DNS-only traffic, or the edge service when traffic is proxied.
Recommended Free Tools
Special offer. See more information about Outbyte and uninstall instructions. Please review EULA and Privacy policy. -
Remove certificate-validation blockers
Automatic certificate issuance can fail even after DNS appears correct. Check that:
wwwresolves publicly to the expected service.- DNSSEC is valid; a broken signature can make a correct record appear unreachable.
- CAA records, if present, authorize the certificate authority you are using.
- Firewall, access-control, authentication, bot, or redirect rules do not block the validation path, especially
/.well-known/*.
Cloudflare’s domain-control-validation troubleshooting identifies these conditions as common blockers. Temporarily exempting the validation path from authentication or aggressive security rules is often necessary; restore the intended protection after issuance if your platform requires it.
Rank #3
NETGEAR Nighthawk WiFi 6 Router R6700AX, Up to 1,500 sq ft, 1.8 Gbps | Reliable Performance, Easy Set Up, 20 devices, 4× Gigabit Port, Dual Band, AX1800- NIGHTHAWK WIFI 6 ROUTER FOR YOUR WHOLE HOME: Delivers fast, reliable WiFi across every room of your apartment or small home for streaming, gaming, video calls, and smart home devices, all running at the same time without slowing each other down.
- WORKS WITH YOUR EXISTING INTERNET SERVICE: Pairs with your existing modem or gateway via ethernet. Compatible with most cable, fiber, DSL, and satellite providers. Some gateways and modem router combos may require bridge mode. No coax needed.
- SET UP AND MANAGE YOUR NETWORK WITH THE NIGHTHAWK APP: Download the free Nighthawk app on iOS or Android for guided setup. Manage WiFi, run speed tests, pause devices, and set up guest networks from anywhere. Active internet required.
- READY FOR THE DEVICES YOU ALREADY OWN: Your phones, laptops, and TVs work right out of the box. WiFi 6 delivers speeds up to 1.8 Gbps across 2.4 GHz and 5 GHz bands. Backward compatible with WiFi 5 and earlier.
- COVERAGE IN EVERY ROOM: Covers up to 1,500 sq. ft. for up to 20 connected devices. Walls, floors, and interference can reduce range. Larger or multi-story homes may benefit from a NETGEAR Orbi mesh WiFi system.
-
Separate a local problem from a public DNS problem
DNS_PROBE_FINISHED_NXDOMAINmeans the resolver concluded that the name does not exist, but the cause can be local or authoritative. Test the hostname from a second network, such as a phone connection, and with more than one resolver. If other networks resolve it while one computer does not, flush that device’s DNS cache, restart the local resolver, or inspect VPN and security software. If every independent test returns NXDOMAIN, inspect delegation and the authoritative zone instead of changing browser settings.
A, AAAA, and CNAME: which www record should you use?
Use the type your hosting provider documents. The records are not interchangeable labels for the same thing.
| Record | What it contains | Use it when | Operational consideration |
|---|---|---|---|
| A | An IPv4 address | Your host gives you a fixed IPv4 endpoint. | Changes to the host’s IPv4 address require an updated record. |
| AAAA | An IPv6 address | Your host gives you an IPv6 endpoint and supports IPv6 traffic. | A stale AAAA record can send IPv6 users to the wrong server even when the A record is correct. |
| CNAME | Another hostname | A managed platform instructs you to delegate www to its hostname. | The target hostname must continue to resolve; do not replace it with a guessed IP. |
An apex domain often has provider-specific restrictions on CNAME records, while a subdomain such as www is normally eligible for a CNAME. Follow the authoritative provider’s interface and your host’s exact instructions rather than creating multiple competing record types.
Choose a canonical URL: www or the apex
Neither form is inherently faster or more correct. The important property is consistency: one public URL should be preferred, and the other should redirect to it.
| Choice | Configuration | Advantages | Risks if configured poorly |
|---|---|---|---|
| www-canonical | Serve https://www.example.com; redirect https://example.com to it. |
The www hostname is a clear subdomain boundary and can be moved to different infrastructure independently of the apex. | The www record and host mapping must remain present; omitting either breaks the canonical address. |
| apex-canonical | Serve https://example.com; redirect https://www.example.com to it. |
The shorter address is displayed to visitors. | Both the apex and www still need DNS, host mapping, and certificate coverage before the redirect works. |
Use one permanent redirect after confirming both HTTPS endpoints work. Update internal links, sitemap entries, canonical tags, cookies, and analytics settings to the same hostname. A redirect loop usually means two layers disagree—for example, an origin redirects to the apex while an edge rule redirects back to www—or an HTTPS-aware proxy is being treated as plain HTTP by the origin.
Direct origin or proxied CDN: what changes?
A DNS-only design sends the browser to the origin address returned by DNS. The origin server presents the certificate and handles the HTTP request. In a proxied design, DNS returns the edge service’s address; the edge presents the public certificate and then connects to the origin according to the configured TLS mode.
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 →Repair Windows errors before they cause bigger problemsFix Now →Rank #4
- 𝐅𝐮𝐭𝐮𝐫𝐞-𝐏𝐫𝐨𝐨𝐟 𝐘𝐨𝐮𝐫 𝐇𝐨𝐦𝐞 𝐖𝐢𝐭𝐡 𝐖𝐢-𝐅𝐢 𝟕: Powered by Wi-Fi 7 technology, enjoy faster speeds with Multi-Link Operation, increased reliability with Multi-RUs, and more data capacity with 4K-QAM, delivering enhanced performance for all your devices.
- 𝐁𝐄𝟑𝟔𝟎𝟎 𝐃𝐮𝐚𝐥-𝐁𝐚𝐧𝐝 𝐖𝐢-𝐅𝐢 𝟕 𝐑𝐨𝐮𝐭𝐞𝐫: Delivers up to 2882 Mbps (5 GHz), and 688 Mbps (2.4 GHz) speeds for 4K/8K streaming, AR/VR gaming & more. Dual-band routers do not support 6 GHz. Performance varies by conditions, distance, and obstacles like walls.
- 𝐔𝐧𝐥𝐞𝐚𝐬𝐡 𝐌𝐮𝐥𝐭𝐢-𝐆𝐢𝐠 𝐒𝐩𝐞𝐞𝐝𝐬 𝐰𝐢𝐭𝐡 𝐃𝐮𝐚𝐥 𝟐.𝟓 𝐆𝐛𝐩𝐬 𝐏𝐨𝐫𝐭𝐬 𝐚𝐧𝐝 𝟑×𝟏𝐆𝐛𝐩𝐬 𝐋𝐀𝐍 𝐏𝐨𝐫𝐭𝐬: Maximize Gigabitplus internet with one 2.5G WAN/LAN port, one 2.5 Gbps LAN port, plus three additional 1 Gbps LAN ports. Break the 1G barrier for seamless, high-speed connectivity from the internet to multiple LAN devices for enhanced performance.
- 𝐍𝐞𝐱𝐭-𝐆𝐞𝐧 𝟐.𝟎 𝐆𝐇𝐳 𝐐𝐮𝐚𝐝-𝐂𝐨𝐫𝐞 𝐏𝐫𝐨𝐜𝐞𝐬𝐬𝐨𝐫: Experience power and precision with a state-of-the-art processor that effortlessly manages high throughput. Eliminate lag and enjoy fast connections with minimal latency, even during heavy data transmissions.
- 𝐂𝐨𝐯𝐞𝐫𝐚𝐠𝐞 𝐟𝐨𝐫 𝐄𝐯𝐞𝐫𝐲 𝐂𝐨𝐫𝐧𝐞𝐫 - Covers up to 2,000 sq. ft. for up to 60 devices at a time. 4 internal antennas and beamforming technology focus Wi-Fi signals toward hard-to-reach areas. Seamlessly connect phones, TVs, and gaming consoles.
| Aspect | DNS-only (direct origin) | Proxied/CDN |
|---|---|---|
| Public DNS answer | Origin IP address or a host-resolved address. | Edge service address. |
| Public certificate | Presented by the origin. | Presented by the edge; the origin may also need a separate certificate for the edge-to-origin connection. |
| Typical www failure | Origin lacks a www certificate or virtual-host entry. | Edge certificate is not active for www, proxy status is inconsistent, or origin TLS does not match the edge configuration. |
| Diagnostic focus | Origin DNS, virtual host, firewall, and TLS configuration. | Edge hostname mapping, proxy status, edge certificate, and origin TLS. |
Cloudflare lists missing certificate coverage and unproxied DNS records among common causes of VERSION_OR_CIPHER_MISMATCH. Check whether www is proxied or DNS-only, confirm certificate activation at that layer, and then verify origin TLS when traffic is sent directly to the server.
Diagnose the error you see
| Browser or server result | Likely layer | What to check |
|---|---|---|
DNS_PROBE_FINISHED_NXDOMAIN or “name not resolved” |
DNS or local resolver | Authoritative delegation, the www record, DNSSEC, and results from another network and resolver. |
| 404, 401, or a different site | Host mapping or origin virtual host | Add www in the hosting dashboard; check the web server’s hostname configuration and application allow-list. |
| Certificate name mismatch | TLS certificate coverage | Inspect the certificate’s SAN list and issue or activate one containing www.example.com. |
VERSION_OR_CIPHER_MISMATCH |
Edge/origin TLS and proxy mode | Confirm proxy status, edge certificate activation, supported TLS settings, and origin certificate when the connection is direct. |
| Redirect loop | Conflicting redirect layers | Identify whether the origin, CDN, or application redirects; choose one canonical URL and align scheme detection. |
| Certificate issuance or renewal fails | Domain-control validation | Check public DNS, DNSSEC, CAA authorization, and access to /.well-known/*. |
Practical tests before and after the change
Run tests from a terminal as well as a browser. Replace the example domain with yours.
- Query the www record: use
dig www.example.com A,dig www.example.com AAAA, anddig www.example.com CNAMEon macOS or Linux. On Windows, usenslookup -type=A www.example.comand repeat forAAAAandCNAME. An answer from the authoritative service should match the value your host supplied. - Compare resolvers: query a resolver you normally use and an independent public resolver. If answers differ, caching, delegation, DNSSEC, or a stale record may be involved; do not assume the browser is at fault.
- Check HTTP behavior: run
curl -I http://www.example.comandcurl -I https://www.example.com. Confirm that the status andLocationheader show the one intended redirect, or that the preferred hostname returns the expected success response. - Inspect the certificate: in a browser, open the padlock and view certificate details. Confirm that
www.example.comappears in the SAN list and that the certificate is currently valid. For a command-line check,openssl s_client -connect www.example.com:443 -servername www.example.comrequests the certificate using the correct SNI name. - Test the origin separately when using a proxy: use the host’s documented origin-testing method. The public edge can be healthy while the edge-to-origin connection fails, or vice versa; keep those paths separate in your diagnosis.
DNS caches can preserve an earlier answer until their record lifetime expires. During that interval, different networks may temporarily observe different states. Continue testing from more than one resolver, but do not repeatedly edit the zone in response to a single cached result.
Common configuration mistakes and their fixes
The record was added at the registrar, but the domain uses different nameservers
Verify active nameservers first. Move the record to the DNS provider those nameservers identify, or intentionally change delegation and wait for that delegation change to take effect. A record in an unused zone has no public effect.
A CNAME and A/AAAA records conflict
Remove obsolete records for the same www name and keep the single arrangement required by the host. A CNAME delegates the name; an A or AAAA binds it to an address. Mixing old and new instructions can produce inconsistent answers.
DNS works, but the host returns a default page
Map www in the hosting control panel and add it to the origin’s virtual-host configuration. Check that the application is not rejecting the Host header or requiring a separate site identifier.
Best Value
- Dual band router upgrades to 1200 Mbps high speed internet (300mbps for 2.4GHz plus 900Mbps for 5GHz), reducing buffering and ideal for 4K stream
- Full Gigabit Ports - Gigabit Router with 4 Gigabit LAN ports, ideal for any internet plan and allow you to directly connect your wired devices
- Boosted Coverage - Four external antennas equipped with Beamforming technology extend and concentrate the Wi-Fi signals
- MU-MIMO technology - (5GHz band) allows high speeds for multiple devices simultaneously
- Access Point Mode - Supports AP Mode to transform your wired connection into wireless network, an ideal wireless router for home
Only www has an SSL warning
Compare the certificate names for the apex and www. Obtain coverage for both names if both are reachable, then activate the certificate at the correct TLS termination layer. A certificate for the apex alone cannot validate a www visit.
HTTP works but HTTPS fails during certificate issuance
Make sure the validation URL is publicly reachable, DNSSEC validates, and CAA records permit the selected certificate authority. Remove rules that force authentication, block automated validation, or redirect /.well-known/* somewhere inaccessible.
The redirect keeps bouncing between www and the apex
List every redirect rule at the CDN, origin, web server, framework, and application. Delete duplicates, set one canonical destination, and ensure the origin correctly reads the original HTTPS state from the proxy. Test with headers using curl -I until one request produces one predictable destination.
When the problem is local rather than your DNS zone
If the site works on a different network but not on one computer or office connection, investigate the local path before changing public records. Flush the operating system’s DNS cache, restart the local router or resolver, disable a VPN temporarily, and check security software that intercepts DNS or HTTPS. Compare the result with a mobile connection and independent resolvers. A local NXDOMAIN or stale answer should not lead you to delete a correct authoritative record.
Conversely, if every network reports NXDOMAIN, the issue is almost certainly public DNS: a missing www record, incorrect nameserver delegation, a typo in the record name, or an invalid DNSSEC chain. Correct that authoritative condition first; browser cache clearing cannot create a DNS record.
Final verification checklist
- The domain’s active nameservers point to the DNS zone you edited.
www.example.comhas the A, AAAA, or CNAME value specified by the host, with obsolete conflicts removed.- The hosting platform and origin virtual host explicitly accept www.
- Both apex and www resolve before either is redirected.
- Your chosen canonical hostname is documented in redirects, internal links, sitemap, cookies, and analytics.
- The certificate SAN list covers every hostname users can reach over HTTPS.
- DNSSEC and CAA settings do not block certificate validation.
/.well-known/*remains reachable for validation.- Proxy status, edge certificates, and origin TLS agree with whether traffic is direct or proxied.
- Independent networks and resolvers show the same intended DNS and redirect behavior.
Once those checks pass, a visitor who types either form of the address will reach the same site securely, with one consistent URL serving as the canonical destination.
Quick Recap
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.
