A sudden drop in website traffic can be worrying.
For many businesses, their website is an important source of enquiries, customers and revenue. So when visitor numbers decline, one of the first questions owners ask is:
“What caused this?”
With the rise of AI search, AI Overviews, AI Mode, ChatGPT and other AI-powered tools, some businesses may immediately wonder:
“Is AI search causing fewer people to visit my website?”
This is a reasonable question.
However, as explained in our guide My Website Traffic Has Dropped. Is AI Search the Reason?, a traffic decline should be investigated rather than automatically attributed to one cause.
A drop in traffic is an observation.
It is not a diagnosis.
There are many possible explanations:
- Google ranking changes;
- search result changes;
- AI-generated answers;
- website updates;
- technical problems;
- competitor improvements;
- changes in customer behaviour;
- seasonal demand changes.
This timeline is designed as a supporting resource for investigating traffic changes.
It provides dates and explanations of significant search, AI and digital events that may be worth comparing against your own analytics.
The purpose is not to say:
“This event caused my traffic decline.”
Instead, it helps you ask:
“Did anything significant happen around the same time as my website performance changed?”
A correlation can provide a useful clue.
It does not prove causation.
How to use this timeline
When investigating a decline in website traffic:
- Identify when the change started.
- Compare that date against the events below.
- Review which pages and traffic sources were affected.
- Investigate further before deciding on the cause.
For example:
- A traffic decline during a Google core update may justify reviewing rankings and content quality.
- A fall in informational traffic while AI search expands may justify investigating AI visibility.
- A sudden drop after a website redesign may suggest a technical issue.
The timeline is a starting point for investigation, not an automatic explanation.
Official sources for monitoring search changes
Google provides official information about search updates through:
- Google Search Central Blog — announcements about Search updates, features and guidance.
- Google Search Status Dashboard — confirmed Search incidents and service issues.
- Google Search’s Core Updates Guidance — Google’s advice on assessing changes after core updates.
Timeline of significant events
March 2024 — Google Core Update and Helpful Content Changes
Date: March 2024
Google released a major core update alongside changes aimed at improving search quality and reducing unhelpful content.
Google explained that core updates are broad improvements to its ranking systems and that websites affected should review the quality and usefulness of their content rather than look for a single technical fix.
Why investigate this event?
If your traffic changed around this period, review:
- which pages lost visibility;
- whether those pages genuinely helped users;
- whether competitors now provide stronger answers;
- whether content was created mainly for search engines rather than people.
August 2024 — Google Core Update
Date: August 2024
Google released another broad core update.
Why investigate this event?
If traffic changed during this period, compare:
- Search Console impressions;
- rankings;
- affected queries;
- competitor visibility.
A core update may change how Google evaluates relevance, quality and usefulness.
It does not automatically mean a website has been penalised.
November 2024 — Google Core Update
Date: November 2024
Google released another broad core update.
Why investigate this event?
Review whether:
- specific topics declined;
- particular pages lost visibility;
- competitors gained positions;
- customer search behaviour changed.
December 2024 — Google Core Update
Date: December 2024
Google released another core update shortly after the November update.
Why investigate this event?
Multiple updates close together can make diagnosis more complicated.
Compare:
- the timing of traffic changes;
- affected pages;
- search queries;
- ranking movements.
Avoid assuming a single event was responsible without evidence.
March 2025 — Google Core Update
Date: March 2025
Google released another broad core update.
Why investigate this event?
If your website changed performance around this period, investigate:
- whether visibility changed across important pages;
- whether customer intent has changed;
- whether competitors now better answer user questions.
June 2025 — Google Core Update
Date: June 2025
Google released another broad core update.
Why investigate this event?
Compare performance before and after the rollout.
Look at:
- traffic sources;
- search impressions;
- ranking changes;
- conversions.
AI search developments
Traditional Google updates are usually announced with clear dates.
AI search changes are often more gradual.
However, they are still important events to consider when investigating changes in customer discovery.
Expansion of AI-generated search experiences
Period: 2024 onwards
Search engines began increasingly incorporating AI-generated summaries and conversational search experiences.
Why investigate this?
AI-generated answers may affect:
- whether users click through to websites;
- which sources are referenced;
- how customers discover businesses.
The impact is likely to vary significantly.
A website receiving traffic from simple informational questions may experience a different effect from a business where customers need detailed comparisons before making a decision.
AI search and customer discovery changes
Period: Ongoing
Customers increasingly have the ability to ask detailed questions directly to AI systems.
Examples:
Instead of:
“accountants Birmingham”
someone may ask:
“Which accountants in Birmingham understand small manufacturing businesses using Xero?”
Instead of:
“dentist Leeds”
someone may ask:
“Which dentists in Leeds are good for patients with severe dental anxiety?”
Why investigate this?
The question is no longer only:
“Do I rank for keywords?”
It is also:
“Does AI understand the situations my customers are experiencing and associate my business with solving them?”
This is where AI visibility testing can provide additional insight.
Website events that can affect traffic
Not every traffic decline is caused by Google or AI.
Your own website changes should always be investigated.
Examples include:
Website redesigns
Possible issues:
- changed URLs;
- lost content;
- altered internal links;
- technical errors.
Domain changes
Possible issues:
- redirects;
- indexing problems;
- lost authority signals.
Content changes
Possible issues:
- removed pages;
- rewritten content;
- changed targeting;
- outdated information.
Tracking changes
Possible issues:
- analytics configuration problems;
- missing data;
- incorrect reporting.
A technical issue can sometimes look similar to a search visibility problem.
Competitor events
Sometimes nothing has changed on your website.
Your competitors simply became more visible.
Investigate:
- Did competitors publish stronger content?
- Did they explain their expertise more clearly?
- Did they answer customer questions better?
- Did they become associated with particular topics?
This is especially relevant in AI search.
A competitor appearing in AI answers may indicate that AI systems have stronger evidence connecting that business with a particular customer need.
Customer behaviour changes
Traffic can also change because customers themselves change.
Possible influences include:
- seasonal demand;
- economic conditions;
- new technology;
- changing preferences;
- new competitors entering the market.
A website can lose traffic even when nothing technical has changed.
The market may have changed.
Using AI visibility testing as part of the investigation
If traditional search data does not fully explain the change, AI visibility testing can provide another perspective.
Questions to investigate:
- Are customers likely to ask AI systems questions related to my business?
- Does AI recognise my expertise?
- Are competitors appearing instead?
- Are important customer questions being answered without mentioning my business?
- Is my business represented accurately?
The aim is not to prove:
“AI caused my traffic decline.”
The aim is to understand whether AI search behaviour may be contributing to changes in customer discovery.
Keep this timeline as a reference point
Search and AI technology continue to evolve.
New events will be added as significant changes occur.
When website traffic changes, the most useful question is not:
“What update caused this?”
It is:
“What changed, when did it change, and what evidence supports the likely explanation?”
A good investigation combines:
- analytics data;
- Search Console data;
- website history;
- competitor analysis;
- customer behaviour;
- AI visibility testing.
The goal is not to find a quick answer.
The goal is to understand what actually happened.