IPv6 for small business websites used to be something you could safely ignore. That is no longer quite true: more than half of UK internet users can now connect over IPv6, and two of the biggest UK broadband providers put around nine in ten of their customers on it. This guide explains what IPv6 means for your website, whether you need an AAAA record, how hosting and CDNs handle it, the email rules that catch people out, and how to test your own setup.
Key takeaways
- APNIC puts 54.3% of UK users as IPv6-capable, but almost every UK user can still reach IPv4-only sites.
- Only publish an AAAA record if that server serves the same site and certificate as your IPv4 address.
- A stale AAAA record left after moving hosts is the most common cause of IPv6 visitors seeing the old site.
- If your web server sends email over IPv6, add the address to SPF and set a matching PTR record, or Gmail may reject it.
What is IPv6 and why does it matter?
Every device on the internet needs an address. The original system, IPv4, has about 4.3 billion addresses written like 203.0.113.10, and they ran out years ago. IPv6 (you can explore how its prefixes and ranges work with our subnet calculator) uses much longer addresses, written like 2001:db8:85a3::8a2e:370:7334, with enough room for every device for the foreseeable future.
The two run side by side, which is called dual stack. A visitor's device connects over IPv6 if both ends support it and falls back to IPv4 if not.
In DNS, the two address types use different records:
| Record | Points to | Example |
|---|---|---|
| A | An IPv4 address | example.com. A 203.0.113.10 |
| AAAA | An IPv6 address | example.com. AAAA 2001:db8::10 |
Our guide to DNS records covers the other record types.
How many UK users have IPv6?
Globally, the Internet Society reported that Google users reaching it over native IPv6 passed 50% for the first time on 28 March 2026.
APNIC publishes these figures for every country, so check yours on its site. For the UK, APNIC's measurements (30-day average, October 2026) put 54.3% of UK users as IPv6-capable. The picture varies enormously by provider:
| UK network | IPv6-capable users |
|---|---|
| Sky Broadband | 93.5% |
| Vodafone (AS5378) | 90.0% |
| BT | 89.9% |
| Hyperoptic | 77.3% |
| Community Fibre | 70.4% |
| Three | 49.2% |
| Zen Internet | 30.4% |
| O2 broadband | 1.0% |
| Plusnet | 0.7% |
| Virgin Media | 0.7% |
| TalkTalk | 0.5% |
Two things follow. First, a large share of your UK visitors on Sky, BT and Vodafone can reach you over IPv6 today. Second, almost every UK user can still reach you over IPv4, because major networks such as Virgin Media and TalkTalk are close to IPv4-only. No UK small business website will lose visitors today for lacking IPv6, but the balance is shifting.
Does your website need an AAAA record?
Short answer: it is good practice, but a broken AAAA record is worse than none at all.
Benefits of IPv6 for a website
- Direct connections for IPv6 users. Without IPv6, those users' traffic may pass through their provider's translation systems to reach your IPv4 address. That works, but adds a step you do not control.
- Future-proofing. IPv6-only networks exist, especially on mobile. They rely on translation to reach IPv4-only sites.
- Accurate visitor IPs. Rate limits and security tools work better when they see real addresses rather than shared translated ones.
The risk: a stale or broken AAAA record
Browsers often prefer IPv6 when it is available. If your domain has an AAAA record that points to the wrong server, or a server that does not listen on IPv6, visitors with IPv6 may get a slow fallback, an old version of the site or an error, while you test on an IPv4 connection and see nothing wrong.
The most common cause is moving hosts. The A record gets updated to the new server, but an old AAAA record still points to the previous host. Some users then see the old site, or a certificate error, depending on their provider.
Rule of thumb: only publish an AAAA record if the server at that address serves the same site, with the same certificate, as your IPv4 address. If in doubt, remove it until you can test properly.
IPv6 on common hosting and website platforms
| Platform | What happens |
|---|---|
| Cloudflare (proxied records) | IPv6 compatibility is on by default; Cloudflare publishes AAAA records and connects to your origin over IPv4 if needed |
| Shopify, Wix, Squarespace | Managed by the platform; you do not add AAAA records yourself unless their DNS instructions say so |
| cPanel shared hosting | Depends on the host; some assign an IPv6 address per account, others offer none |
| VPS or cloud server | Usually available but may need enabling on the server and in the firewall |
Cloudflare
Cloudflare says that "by default, IPv6 compatibility is turned on for your domain" for proxied DNS records, on every plan. It creates AAAA records automatically, so IPv6 visitors can reach your site even if your origin server only has IPv4. For most small businesses using Cloudflare's proxy, IPv6 is already handled. Only Enterprise customers can switch it off; others whose origin only understands IPv4 addresses in logs or headers can use Cloudflare's Pseudo IPv4 setting.
If your records are DNS-only (grey cloud), Cloudflare does not do this, and any AAAA record you add must point to a server that really serves your site over IPv6.
Your own server
If you run Nginx, make sure it listens on IPv6 as well as IPv4:
server {
listen 443 ssl;
listen [::]:443 ssl;
server_name example.com www.example.com;
# ...
}
For Apache, Listen 443 usually binds to both IPv4 and IPv6 on modern systems. Also allow ports 80 and 443 in your IPv6 firewall rules (for example ip6tables or the IPv6 rules in your cloud provider's security group), which are often separate from the IPv4 rules.
IPv6 and email: the part that catches people out
Email is where IPv6 causes the most real-world problems for small businesses. If a mail server sends over IPv6 without the right DNS records, Gmail may reject the message.
Google's IPv6 sending rules
Google's sender guidelines say the sending server's public IP address "must have a corresponding PTR record that resolves to a hostname", and that hostname must have a matching A record (IPv4) or AAAA record (IPv6) pointing back to the same IP. Google also gives a specific bounce for IPv6 failures:
Message does not meet IPv6 sending guidelines regarding PTR records and authentication.
All senders also need SPF or DKIM, and bulk senders need SPF, DKIM and DMARC.
Who is affected?
- Google Workspace and Microsoft 365 users sending through those services: the provider manages its own sending IPs and reverse DNS, so you only need correct SPF, DKIM and DMARC for your domain.
- Website contact forms and WooCommerce order emails sent directly from your web server: this is the risky case. If the server has an IPv6 address, it may send over IPv6 without a PTR record or an SPF entry for that address.
- Self-managed mail servers on a VPS: you are responsible for PTR records on both IPv4 and IPv6.
Fixing IPv6 email problems
- Add the IPv6 address to SPF if the server sends mail directly:
v=spf1 ip4:203.0.113.10 ip6:2001:db8::10 include:_spf.google.com ~all
- Set a PTR record for the IPv6 address. Reverse DNS is controlled by whoever owns the IP, usually your hosting provider, not your DNS host. Ask them to set it to your mail hostname, then make sure that hostname has a matching AAAA record. To see what an address currently resolves back to, look it up with our IP lookup tool.
- Or stop sending over IPv6. In Postfix, setting
inet_protocols = ipv4inmain.cfforces outgoing mail over IPv4. - Better still, send website email through an authenticated service such as your Google Workspace or Microsoft 365 account, or a transactional email provider, using SMTP authentication from a plugin.
Check the results with our SPF checker and email deliverability checker (free account required). Our guide to why emails go to spam covers the other common causes.
How to test IPv6 on your website
1. Check your DNS records
Use our DNS lookup tool (free account required). It lists your A, AAAA, NS, MX, TXT, SOA, CAA and CNAME records together, so you can see straight away whether an AAAA record exists and whether it matches your current host. From a terminal:
dig AAAA example.com +short
dig AAAA www.example.com +short
Check both the root domain and www, since they can differ.
2. Check the site actually loads over IPv6
From a machine with IPv6 connectivity:
curl -6 -sI https://example.com | head -1
A 200 or 301 response means the site answers over IPv6. A timeout or connection refused means the AAAA record points somewhere that is not serving your site, so fix or remove it.
3. Compare with IPv4
curl -4 -sI https://example.com | head -1
Both should return the same status and, if you check the full response, the same site.
4. Test your own connection
Sites such as test-ipv6.com show whether your own broadband supports IPv6. If you are on Virgin Media or TalkTalk, you probably cannot test IPv6 from the office and will need a server, a mobile hotspot on a network with IPv6, or an online tool.
5. Check your mail server's reverse DNS
dig -x 2001:db8::10 +short
The result should be your mail hostname, and that hostname's AAAA record should point back to the same address.
To catch a stale AAAA record, broken redirects and certificate problems together, run a free website audit. Our DNS health check reports AAAA records alongside nameserver redundancy, CAA and DNSSEC.
Frequently asked questions
Do I need IPv6 for my small business website?
It is not essential yet, because almost all UK users can still reach IPv4 sites. It is good practice, and if you use Cloudflare's proxy it is already switched on. The important thing is never to publish an AAAA record that points to the wrong server.
Will IPv6 make my website faster?
Not noticeably in most cases. The main benefit is that IPv6 users connect directly instead of through their provider's translation systems. Speed depends far more on hosting, page weight and caching.
Why can some people not see my updated website after a host move?
A common cause is an old AAAA record still pointing at the previous host. Visitors whose provider uses IPv6, such as Sky or BT customers, may reach the old server while IPv4 users see the new one. Update or remove the AAAA record.
Does IPv6 affect SEO?
Google has not said that IPv6 is a ranking factor. It matters indirectly: if a broken AAAA record makes your site unreachable for some users or crawlers, that can cause errors and lost visits.
What is an IPv6 PTR record and do I need one?
A PTR record maps an IP address back to a hostname. If your server sends email over IPv6, Google requires a PTR record for that IPv6 address with a matching AAAA record, or messages may be rejected. Your hosting provider usually sets it.
Sources
Written by the MakeItFlow team
We build the website audit these guides are based on. Every fact is checked against the primary sources listed above and this guide was last reviewed on 31 October 2026 . How we research and check
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