Ask buyers how long their analytics migration took and almost none give a build time. Of the analytics moves described as done in these interviews, only a handful say how long the switch took. What buyers describe instead is a second clock that starts at go-live: unless history is preserved or the new tool started collecting early, it has no comparable history of its own, so year-over-year comparisons can wait about a year; reports and dashboards have to be rebuilt; and the numbers are not trusted until the tracking has been checked. As with CDPs, go-live is not the finish. Moving from Adobe Analytics to Customer Journey Analytics, inside one vendor, reads as a migration rather than an upgrade, and none of those moves here was reported complete — some were under way, others still planned. Among projects with a plan and a later status, none finished early — the same pattern buyers describe for email, commerce, loyalty and CMS platforms. The companion reads are why teams switch product analytics tools and what product analytics buyers wish they'd known, where the ratings live.
Why analytics migrations take longer than planned
The history doesn't come with you
Historical reporting is the challenge buyers describe most often, and the one particular to analytics. A new implementation does not automatically inherit comparable measurements from the system it replaces. If the company cannot preserve or reconcile the old data, it may need roughly a year of collection before it has a complete year-over-year baseline within the new tool. Teams that began collecting early, kept historical exports or ran both systems sometimes avoided the full gap, although metrics across platforms may still need careful reconciliation. “A lot of businesses, especially ours, are very seasonal, so you really need a year-over-year comparison in order to evaluate performance,” one beauty brand explains. A retailer that moved a year before its interview said “we only put Adobe Analytics in a year ago, so we just got to the point where we have a year-over-year comparison.” Where history was lost, the gap lasts: “we have loss of data, so we can't do year-on-year comparisons going back more than a year and a half,” another retailer says of its GA4 move. Even a planned move involves “work to retag the website and ensure that we don't lose historical data, which was a difficult point.”
Named in this context: GA4 · Adobe Analytics · Universal Analytics
Every report and dashboard has to be rebuilt
The tool goes live empty of the reports the business used. A company running fourteen sites describes “just creating the reports and the views and getting a lot of our custom dimensions set up,” and adds, “I feel like it's still in progress, even though we're almost two years removed from when we migrated to GA4.” An apparel brand remembers a pre-holiday rush: “we really built a lot of dashboards because we moved to GA4 and that was a nightmare.”
Named in this context: GA4 · Adobe Analytics · Customer Journey Analytics
The numbers aren't trusted yet
Until events are firing correctly and reconcile with other systems, teams keep using something else. A marketplace says “it also took us a long time to get our stuff together when it comes to our events and making sure that, A, they were firing properly, but B, that GA4 was a trustworthy tool that we could use” — and for conversions, “We don't really trust conversion data, so we don't use GA4 for conversion.” Why tracking is hard to trust is on top complaints about product analytics and GA4 alternatives; this page is about how long it takes to arrive.
Named in this context: GA4 · implementation partners
Nobody is free to finish it
Analytics migrations compete with everything else for the same few people. A travel company's leader puts it plainly: “the challenge with all these migrations is that they require a year of work, which is very hard to prioritize with so much going on in the business.” A hospital system that replaced Google is “only using about 20% of the value of that product because we don't have an analyst.” Teams new to a platform bring in help — “we need to partner with an external service provider and professional services that help us with the implementation,” a financial services firm says of its Adobe move.
Named in this context: Customer Journey Analytics · Adobe Analytics · GA4
Retagging takes longer than expected
Events and variables have to be redesigned and re-implemented, not just copied. A global brand says its GA4 move “went on way longer than it should have, and just the retagging and all of it.” An insurer finds that “Tagging strategy and variable allocation is complicated inside the Adobe stack, so it has to be architected over time, and that's taken a lot longer than I think a lot of people anticipated.” Even a small setup can drag: one brand's session-replay tool is “still not set up, and we've been chasing this for about a month now.”
Named in this context: Adobe Analytics · GA4 · session replay tools
Approvals and privacy reviews set the pace
In regulated businesses, and in large ones, the build waits on review. One company's GA4 move “took over a year to get through the IT team approvals process.” Health systems that switched Google off for privacy describe a gap rather than a migration: one says “when we had to disable and detach from Google, we were kind of flying blind,” and another relied on a site-quality tool “until we turned GA4 back on this past year.” Privacy reviews for session replay are covered on what is session replay software.
Named in this context: GA4 · Google Analytics · Siteimprove · Customer Journey Analytics
How long does an analytics implementation take?
These interviews do not establish a typical implementation duration, because buyers rarely report a complete timeline from project start to cutover. Three describe useful but different milestones: about five months of overlap between product-analytics tools, a GA4 transition lasting at least eighteen months including more than a year of IT approvals, and a multi-brand Adobe Analytics implementation taking about two years — “It took us two years to implement Adobe Analytics, so in the interim, we leveraged Hotjar as a very simple out-of-the-box solution.” The first measures parallel operation rather than necessarily the entire migration. The clock buyers talk about more often is the one after go-live: without usable history, about a year before a new tool has a comparable year of its own data, and in some cases years before the tracking is fully trusted. Read the figures as examples, not benchmarks.
How long did the move from Universal Analytics to GA4 take?
Google retired Universal Analytics in 2023 and its paid version a year later, so for most companies the switch happened on Google's date; the work came after it. Buyers describe months of hand-weighted comparisons until GA4 had a year of its own, a GA4 setup broken for most of a year, reports and custom dimensions still being rebuilt two years on, and history that was lost. The longest account here is a global supplier that declared GA4 live in mid-2023 and was still paying outside help to fix it at the end of 2025, told below. The one move with a plan and an outcome that met its date — a cutover from Google's paid tier to another tool before the sunset — still did not do everything it needed six months later; as with commerce replatforms, hitting the date meant switching before the new tool had caught up. What buyers dislike about GA4 itself is on GA4 alternatives.
Is moving to Customer Journey Analytics an upgrade?
Not in buyers' telling. The companies discussing a move from Adobe Analytics to Customer Journey Analytics describe it as a substantial transition rather than a routine software upgrade. Some were already implementing it, with elapsed periods described as nine months or most of a year; others expected to begin or complete a move within the next year or two. None was reported complete in these interviews. One buyer says “that implementation is not an upgrade; it's basically a switchover,” and another reports a limitation in the reporting window available to their team: “One drawback, I would say, is that it's only a 13-month reporting window.” A financial services company planning the move expects that the work “would require running Adobe Analytics and Customer Journey Analytics side by side for an extended period of time.” As with CMS version changes, staying with the vendor does not avoid a migration. Why buyers move to it is on Adobe Analytics alternatives.
Do analytics migrations stay on schedule?
Not in the cases with usable timing comparisons here. Nine projects have both an identifiable plan and a later status, and none finished early. One finished on time, because the vendor set the date, and it switched before the new tool did everything the old one had. Five ran longer than planned — three of them described only as longer than expected, without a planned figure — one stalled waiting for a hire, and two were pushed back before the build began. This small, selectively reported group cannot establish how often analytics migrations miss their dates overall, and no overrun here can be sized against its plan. The pattern matches what buyers describe for email, commerce, loyalty and CMS platforms.
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The counter-current: the moves that went smoothly
The smoother moves here did one of a few things. Some started the new tool long before they needed it — “fortunately the data team was smart enough to implement GA4 well over a year ago,” one apparel brand says, so “once we made that transition, we were able to have at least year over year.” Some kept the history: “in anticipation of sunsetting UA360, we kept a backup, a hard copy backup of a year's worth of history,” and another team did “a very, very aggregated historical export this year particularly because all the access to the Universal Analytics properties was expiring.” Some ran old and new together for a while: “there was a period of time where there was overlap between the two solutions.” And lighter tools are quick — “configuring an application on Hotjar literally takes about two weeks, a week or two weeks.” Nothing quick here involved re-instrumenting an enterprise estate or moving to Customer Journey Analytics.
What this means for your migration plan
In these interviews the length of an analytics migration is set less by the cutover than by what follows it: history, reports, trust and the people to do the work. One buyer here started the new tool collecting more than a year before switching, and had year-over-year comparisons on day one. Our recommendations, beyond that, not practices most buyers describe: decide which history you need and export or back it up before the old tool is switched off; run both tools side by side long enough for the new one to build its own history; rebuild the reports the business actually uses before cutover, not after; name who will own tagging and reporting on the new tool before you sign; and in a regulated business, start the privacy and IT review before the build is scheduled. For the reasons teams move, see why teams switch product analytics tools; for cost, what analytics buyers actually pay.
Common questions
How long does an analytics implementation take?
These interviews do not establish a typical duration. Few buyers report a complete timeline; three describe different milestones: about five months of overlap between two product-analytics tools, a GA4 transition of at least a year and a half including more than a year of IT approvals, and about two years for Adobe Analytics across many brands. The longer clock runs afterwards: without usable historical data, a new tool may need about a year of collection before it can produce year-over-year comparisons from its own measurements, and some teams were still fixing tracking years after go-live.
How long did the move from Universal Analytics to GA4 take?
Google set the date, so the switch itself happened when it had to; the work came after it. Buyers describe months of comparing numbers by hand, reports and custom dimensions still being rebuilt two years on, lost history, and in one case GA4 declared live in mid-2023 and still being fixed with outside help at the end of 2025.
Why do analytics migrations take longer than planned?
Buyers most often describe history and year-over-year comparisons that have to be carried over or rebuilt, reports and dashboards that have to be recreated, numbers that are not trusted until events are retagged and checked, and teams with nobody free to finish the job. Among projects with a plan and a later status, none finished early, though this small group cannot show how often analytics migrations miss their dates overall.
Is moving from Adobe Analytics to Customer Journey Analytics an upgrade?
Buyers in these interviews describe it as a switchover rather than an upgrade: reports to migrate, months of work, plans to run both side by side, and for one buyer a shorter reporting window. None was reported complete in these interviews: some were under way, others still planned.
How do you avoid losing year-over-year data when switching analytics tools?
The buyers who managed it started the new tool collecting early — one ran GA4 for over a year before switching — kept a backup or export of the old tool's history, or ran both tools for a period. Deciding what history you need before the old tool is switched off is our recommendation, not a practice most buyers describe.
Can you run two analytics tools at the same time during a migration?
Yes. Buyers describe overlaps from a few months, for a product-analytics move, to an extended period planned for an enterprise move to Adobe Customer Journey Analytics. Running both lets the new tool build up its own history before the old one is switched off.
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