During a migration cutover, you might refresh your site and see the old version, refresh again and see the new one, or find that a colleague sees a different version than you — and it can be alarming, as if something has gone wrong. Nothing has: seeing both the old and new sites during a cutover is completely normal, an inevitable consequence of how DNS propagation works. Understanding why it happens turns a moment of panic into a recognised, expected part of the process. This guide explains exactly what is going on and how to handle it.

You will learn why both sites show during a cutover, why different people see different versions, why you specifically might keep seeing the old site, why this is not a problem (and why you keep both hosts alive because of it), how to control which version you see, and when the dual-showing ends. By the end, this confusing phenomenon will make complete, reassuring sense.

Why both sites show during a cutover

Both the old and new sites show during a cutover because of DNS propagation: when you change DNS to point your domain at the new host, that change spreads across the internet’s caches gradually, not instantly. During the spread, some DNS caches still hold the old record (pointing to the old host) while others have picked up the new record (pointing to the new host) — so the same domain resolves to two different servers depending on which cache answers.

This is why, crucially, you keep the old host running throughout the cutover: because for the duration of propagation, real visitors are genuinely being sent to both hosts. A visitor whose DNS cache still has the old record reaches the old site; one whose cache has refreshed reaches the new site. Both are live and serving traffic simultaneously during the transition window, which is exactly the intended state for a zero-downtime migration.

So both sites showing is not a glitch but the literal, expected mechanics of a DNS cutover: the domain points to two places at once, in different parts of the internet, until propagation finishes and every cache has the new record. Understanding this reframes the phenomenon entirely — it is the visible sign that your cutover is in progress and propagating normally, not evidence that anything has broken. The dual-showing is propagation made visible.

Why different people see different versions

Different people seeing different versions of your site during a cutover follows directly from the propagation mechanics, and it can be striking — you see the new site, a colleague in another city still sees the old one. This happens because each person’s DNS resolution goes through different caches (their ISP’s resolver, their network, their device), and those caches refresh at different times.

Someone whose DNS path has already refreshed and picked up the new record is routed to the new host and sees the new site; someone whose caches still hold the old record is routed to the old host and sees the old site. Since caches around the world refresh independently as their individual TTLs expire, at any given moment during propagation, different people are simply at different points in the switch — hence different versions.

So the fact that different people see different versions is not inconsistency or error; it is the geographically and network-staggered nature of propagation showing up in real experiences. Everyone will converge on the new site as their respective caches refresh, but during the window, which version any given person sees depends purely on whether their particular DNS path has updated yet. This is why you cannot expect everyone to switch at the same instant, and why a propagation checker (which queries many locations) shows exactly this mixed picture.

Why you might keep seeing the old site

A particularly common and confusing experience is that you — the person who made the change — keep seeing the old site even after cutover, sometimes longer than others. There are a few specific reasons this happens to you in particular:

• Your local DNS cache: your own computer caches DNS, so it may hold the old record until that local cache expires or you flush it.
• Your browser cache: your browser may be showing you a cached copy of the old site’s pages, independent of DNS.
• Your ISP’s resolver: your internet provider’s DNS resolver may be holding the old record, sometimes longer than its stated TTL.
• A leftover hosts-file entry: if you used a hosts-file preview earlier and forgot to remove it, your computer is forcing the old (or a fixed) IP regardless of DNS.

So you seeing the old site persistently is usually a local caching quirk on your end, not the state of the migration globally. This is why you should not judge whether propagation is complete by what your single computer shows — check a propagation checker’s global view instead. The fixes are to flush your local DNS cache, clear your browser cache (or use a private window), and check for a forgotten hosts-file entry. Very often, ‘the migration isn’t working, I still see the old site’ is really just your own caches lagging, while the world has already moved on.

Why this isn’t a problem

The reassuring core of all this is that both sites showing during a cutover is not a problem — it is the intended, safe state of a zero-downtime migration. Because you kept the old host running (as you should) and the new site was tested and working before cutover, both hosts are serving working versions of your site during the transition. So whichever version a visitor hits, they get a functioning site; no one meets an error or a dead page.

The dual-showing only becomes a problem if the two versions are meaningfully out of sync in a way that matters — which is why, during the cutover window, you avoid making content changes on either site (so both serve the same content) and, for transacting sites, use strategies like freezing a store to prevent, say, orders landing on the old site. For a static content site, brief dual-showing is entirely harmless, because both versions show the same content.

So the dual-showing itself is benign: it is the mechanism that makes zero-downtime possible, since both hosts working simultaneously is precisely what ensures no visitor meets a gap. The thing to manage is not the dual-showing but keeping the two versions consistent during it, which for most sites simply means not editing content mid-cutover. Understood correctly, both sites showing is a sign the migration is working as designed, not failing — the visible proof of a seamless transition in progress.

Controlling which version you see

While dual-showing is normal, it helps to be able to control which version you are looking at, so you can deliberately check the new site (to verify it) or understand what you are seeing. The most reliable way to force yourself onto the new site — before or during cutover — is a hosts-file entry mapping your domain to the new host’s IP, which makes your computer resolve to the new site regardless of propagation.

To see the current propagated state rather than your own cached version, flush your local DNS cache and clear your browser cache (or use a private/incognito window, which avoids browser caching), so your machine does a fresh lookup. And to see the global picture rather than just your own experience, use a propagation checker, which shows what many locations around the world are resolving to — the true state of the switch beyond your single vantage point.

So you have tools to control and interpret what you see: a hosts-file entry to force the new site, cache-flushing and private windows to see your current real resolution, and a propagation checker for the global view. This means you are never at the mercy of the confusing flip-flop — you can deliberately verify the new site, confirm your own status, or assess overall propagation as needed. Remember to remove any hosts-file entry afterward, so you do not later confuse yourself by seeing a forced version.

When the dual-showing ends

The dual-showing ends when propagation completes — when every DNS cache around the internet has expired its old record and picked up the new one, so the domain resolves to the new host everywhere. At that point, all visitors are routed to the new site, the old host is receiving no more traffic, and the two-versions phenomenon is over: everyone sees the new site.

How long this takes is governed by TTL: if you lowered your TTL before cutover, the dual-showing window is short (minutes to about an hour); if you did not, it runs at your normal TTL and can last several hours, with a small tail of stubborn caches occasionally up to 48 hours. You confirm it has ended by checking a propagation checker showing near-universal resolution to the new host, at which point the transition is effectively complete.

So the dual-showing is a temporary, bounded phenomenon that ends when propagation finishes, and its duration is exactly the propagation window your TTL controls. Once it ends and everyone is on the new site, you give a little margin for any last stragglers and can then safely retire the old host — the point at which the migration is truly done. So both sites showing is the visible signature of the transition, and its disappearance is the signal that the cutover has fully completed. Seeing both is normal; seeing only the new one everywhere means you have arrived.

FAQs

Why do I see both the old and new site during a cutover?

Because of DNS propagation: when you change DNS to the new host, the change spreads across the internet’s caches gradually. During the spread, some caches still point to the old host and some to the new, so the same domain resolves to two different servers depending on which cache answers — both sites are genuinely live at once. It’s the expected mechanics of a cutover, not a glitch, which is why you keep both hosts running.

Why do different people see different versions of my site?

Because each person’s DNS resolution goes through different caches (their ISP’s resolver, network, device) that refresh at different times. Someone whose caches have picked up the new record reaches the new site; someone whose caches still hold the old record reaches the old site. Everyone converges on the new site as their caches refresh, but mid-propagation they’re at different points in the switch.

Why do I keep seeing the old site after cutover?

Usually a local caching quirk on your end, not the global state: your computer’s DNS cache or browser cache holding the old version, your ISP’s resolver lagging, or a forgotten hosts-file entry forcing the old IP. Flush your DNS cache, clear your browser cache (or use a private window), and check for a leftover hosts entry. Judge propagation by a global checker, not what your single machine shows.

Is it a problem that both sites show during cutover?

No — it’s the intended, safe state of a zero-downtime migration. Because you kept the old host running and tested the new one before cutover, both serve working versions, so whichever a visitor hits, they get a functioning site. The only thing to manage is keeping the two versions consistent — avoid editing content mid-cutover, and for stores, freeze orders — so they don’t drift out of sync. The dual-showing itself is benign.

How do I control which version of my site I see?

Force the new site with a hosts-file entry mapping your domain to the new host’s IP (regardless of propagation). See your current real resolution by flushing your DNS cache and clearing your browser cache or using a private window. See the global picture with a propagation checker that queries many locations. Remove any hosts-file entry afterward so you don’t later confuse yourself with a forced version.

When does the dual-showing stop?

When propagation completes — every cache has picked up the new record and the domain resolves to the new host everywhere, so all visitors see the new site. Duration depends on TTL: minutes to about an hour if you lowered it beforehand, several hours (occasionally up to 48 for stragglers) if not. Confirm it’s over with a propagation checker showing near-universal new-host resolution, then retire the old host with a little margin.

The bottom line

Seeing both the old and new versions of your site during a cutover is completely normal — it is DNS propagation made visible, not a sign that anything has broken. When you change DNS to point at the new host, that change spreads across the internet’s caches gradually rather than instantly, so during the transition some caches still send visitors to the old host while others send them to the new, and the same domain genuinely resolves to two servers at once. This is exactly why you keep the old host running throughout the cutover: both hosts are serving real traffic during propagation, which is precisely the state that makes a zero-downtime migration possible. Different people seeing different versions is the same mechanism showing up in individual experiences, as each person’s DNS path refreshes at its own time.

A special case worth recognising is you, the migrator, persistently seeing the old site — which is almost always a local caching quirk (your computer’s DNS cache, your browser, your ISP’s resolver, or a forgotten hosts-file entry), not the global state, so judge propagation by a worldwide propagation checker rather than your single machine, and flush your caches to see the true current resolution. The dual-showing is benign as long as you keep the two versions consistent — which for most sites just means not editing content mid-cutover, and for stores means freezing orders — and you can control what you see with a hosts-file entry (to force the new site), cache-flushing (to see your real resolution), and a propagation checker (for the global view). It all ends when propagation completes and the domain resolves to the new host everywhere, a window your TTL governs — minutes with a lowered TTL, hours without. So both sites showing is the visible signature of a transition working as designed, and its disappearance into a single new site everywhere is the signal that your cutover is truly complete.

When you are ready, you can start with Hostinger and use code PROTIPS for the reader discount. Seeing both old and new sites during a cutover is normal — it’s DNS propagation: caches point to different hosts until they all refresh, so both are genuinely live at once (which is why you keep both hosts running). Different people see different versions for the same reason. You persistently seeing the old site is usually your own cache — flush DNS/browser, check for a leftover hosts entry, and judge by a global propagation checker. It ends when propagation completes.