Gemini vs ChatGPT Market Share: What the Similarweb Data Shows

What does the Gemini vs ChatGPT market share story mean?

Gemini vs ChatGPT market share describes how generative AI website visits split between the two tools. It is a traffic share, so it does not measure users, revenue or answer quality. The headline is simple: ChatGPT still leads, but its share fell sharply in a year while Gemini roughly tripled its own.

This story keeps returning in headlines. However, most coverage quotes one number and drops the context. In this guide we state where the figures come from, how they are measured and where they stop. Then we explain what the Gemini vs ChatGPT market share shift means for your brand and your SEO work.

One caveat first. The numbers below rest on traffic estimates that Similarweb publishes. The latest dataset we could verify covers spring 2026, meaning May and June. If a newer report exists, the figures may already have moved.

What does Similarweb say about Gemini vs ChatGPT market share?

Similarweb tracks the share of visits across generative AI websites worldwide. Its January 2026 report shows ChatGPT at 64.5 percent and Gemini at 21.5 percent. The same report says ChatGPT stood near 86 percent twelve months earlier, while Gemini sat around 5 percent.

The picture shifts further in the May 2026 data. According to Similarweb, ChatGPT fell from roughly 76 percent in June 2025 to roughly 53 percent. Gemini climbed from under 9 percent to about 27 or 28 percent. Claude also rose, from about 2 percent to about 9 percent.

So the headline points in the right direction. Even so, reading it as "ChatGPT is collapsing" would be wrong. A share can fall while total visits keep growing.

What do these figures measure, and what do they miss?

First, Similarweb measures total visits at the domain level. It counts visits to sites such as chatgpt.com or gemini.google.com. The method relies on a panel and a statistical model. Therefore the results are market estimates, not audited official numbers.

Next, it helps to know what falls outside the measurement:

• API usage and enterprise integrations are not counted.
• Assistants built into phones and browsers are not counted.
• Paid subscriber numbers and revenue are not included.
• Answer quality and user satisfaction are not covered.
• Web visits and mobile app use can tell different stories.

In fact, Similarweb's own report states this limit. The January report says API use and embedded assistants sit outside its scope. For that reason we suggest reading "market share" as "web traffic share".

Why is the Gemini vs ChatGPT market share changing?

The sources do not prove a single cause for the Gemini vs ChatGPT market share change. This section is our interpretation, not a verdict. Still, a few factors stand out. Google places Gemini inside its own products and already reaches a very large audience.

Also, the Gemini app opens in one step on phones, in the browser and through a Google account. So users need little effort to form a new habit. Meanwhile, new model releases and image features may have attracted users too.

One point deserves care here. Distribution advantage and product preference are two different things. A person may open Gemini and still finish the job in ChatGPT. Traffic data cannot separate those two behaviours.

Also, product differences matter. Some users like the convenience of a Google account, while others keep the chat experience they know. Traffic data cannot tell us which preference wins. Only user research can answer that.

Is ChatGPT really losing ground?

In share terms, yes. However, a falling share is not the same as a shrinking service. Similarweb's report says visits are growing faster than the audience behind them. In other words, existing users open these tools more often.

When the pie grows, one player's slice can shrink. Meanwhile its total visits can still rise. Example calculation: if 76 of 100 visits go to one tool, and volume doubles while the share falls to 53, visits rise from 76 to 106.

That calculation only shows the logic. It is not a real ChatGPT figure. For instance, many people see the percentage and forget the absolute volume. So track both the share and the total together.

Likewise, the same logic applies to Gemini. A tool whose share rose from 9 to 27 percent probably grew its visits much faster than the total. Still, we do not print a visit count here, because we have no verified absolute number.

As a result, do not treat a falling share as a crisis signal on its own. Read it as a sign that competition and alternatives are growing.

What does the web versus mobile gap show?

However, mobile apps tell a different story in Similarweb's report. Claude and Meta AI show the sharpest US app growth. Gemini, by contrast, grew the slowest of the challengers on mobile.

So this gap shows that web traffic and app use do not mirror the same behaviour. So a decision based on one chart is risky. Instead, test with your own data which device sends your audience to which tool.

Also, read the web and mobile numbers separately. A tool's web share can fall while its app use rises. The reverse can happen too. Your own analytics decide which channel matters for your audience.

For example, B2B buyers often research on desktop. A fashion brand, on the other hand, sees most queries from phones. For these two audiences, the answer to "which tool leads?" can differ.

Why does the Gemini vs ChatGPT market share shift matter for SEO?

People now type questions into chat tools as well as Google Search. So a mention of your brand in these tools opens a new area of visibility. Google's own search features also produce AI answers.

First, Google says its AI features need no separate technical requirements. According to Search Central, standard SEO best practices still apply to them. So you do not need to drop the basics. You can read the source in Google's AI features documentation.

On the other hand, ChatGPT and Gemini may draw on different sources. Rather than optimise for one tool, a steady line of trust and clarity is the safer path. For a wider frame, see our guide on how to write content for AI Overviews.

How much traffic do AI tools send to your site?

However, the share varies a lot from site to site. For many businesses, AI referrals are still a small part of total traffic. So the first job is measuring it on your own site. The global market share does not decide your share.

Similarweb's report holds an interesting detail. After ChatGPT's May 2026 homepage link update, the share of referrals landing on homepages rose from roughly 26 to 29 percent to roughly 62 to 63 percent. The level held through late May.

The meaning is clear: AI tools may send a visitor to your brand's homepage instead of a deep page. Therefore your homepage needs a clear value proposition, service paths and trust signals. Otherwise the new visitor will not know what to do next.

What does ChatGPT's homepage link change mean for your brand?

According to Similarweb, the homepage share of referrals moved from roughly 26 to 29 percent to roughly 62 to 63 percent. When a tool cites a source, it often links to the root domain. You may not see the same effect in every sector.

In that case the homepage has three jobs. First, it states what the brand does on the first screen. Second, it gives a fast path to services and common questions. Third, it makes trust signals visible, such as references, contact details and company information.

So run a quick review of your homepage. Ask the question as a new visitor from an AI tool would: what does this company do, and what is my next step? If the answer is unclear, simplify the page.

How do you track AI traffic in GA4?

First, separate the sources. In the GA4 traffic acquisition report, look for chatgpt.com, gemini.google.com and similar domains. Then group them in a custom channel group. For a step by step setup, read our guide on detecting AI traffic in GA4.

Run these checks while you set it up:

1. List the AI domains in the source and medium report.
2. Merge those domains into one custom channel group.
3. Read conversions and conversion value for that channel on its own.
4. Split landing pages into homepage and deep pages.
5. Pull the same report every month and compare the trend.

One more point: the same person can open several sessions. So read sessions and users separately. Also judge conversions by the target action, not by sessions alone.

Some referrals arrive without source data. In that case the visit appears as direct. Therefore treat the GA4 figure as a lower bound. Links you tag with UTM parameters reduce this gap, and our UTM builder is ready for the job.

Does your brand appear in ChatGPT and Gemini?

You cannot know without testing. First, list fifteen to twenty questions your customers might ask. Then ask each one in ChatGPT and Gemini separately. Note whether your brand appears, which sources are shown and how competitors are placed.

In addition, doing this by hand first is useful. Answers can change over time and between users. So write the results into a table and repeat the test monthly. Our AI visibility checker speeds up that first check.

Then check the details as well. Is your brand described correctly in the answer? Are your services listed correctly? Is any information out of date? If you see a wrong claim, first make sure your own pages state the fact clearly and currently.

For a deeper method, our guides on how your brand shows up in ChatGPT and Gemini and measuring AI visibility are a good start.

How do you prepare content for both tools?

In short, both tools need clear, verifiable and well structured content. In the field we see these habits help. This is an observation from experience, not a guarantee:

• Answer the question directly at the top of the page.
• Write headings from real user questions.
• Add a source and a date next to every figure.
• State brand, author and service details openly.
• Keep tables and lists short and easy to scan.

Then check technical access too. Make sure your robots.txt file does not block AI crawlers by accident. Our guide on AI crawlers explains these settings. If you like, build a sample file with the llms.txt generator.

Also, freshness matters. Show the date, the author and the update note on your pages. Do not leave old figures untouched. AI tools sometimes quote old pages with old facts, and that shows your brand wrongly.

How does the Gemini and Google Search link affect SEO?

Gemini is a Google product, but it is not the same thing as the Google Search ranking system. Still, both live in the same company ecosystem. So content that is visible and trusted in Google may also become a source in Gemini answers.

We do not present this as a guarantee. Google does not say which source appears in which answer. Even so, the practical result is clear. First fix your core SEO health in Google Search. Then add AI visibility as an extra layer.

Speed, indexability, internal linking and content quality apply on both sides. If you have gaps there, invest in them first. This is always our starting point in SEO consulting.

Also, Gemini may use personalisation tied to a Google account. We cannot measure its effect from outside. That uncertainty is one of the best reasons to repeat your test list on a regular schedule.

Which mistakes do people make when reading market share data?

In practice, the most common mistake is treating traffic share as quality or revenue share. Second, people draw a trend from one month of data. Third, they treat secondary news as the source. Most articles rewrite Similarweb's data and trim the context.

We can summarise the mistakes like this:

• Mixing up visit share with the number of users.
• Reading web data as if it covered mobile and API use.
• Treating one month of noise as a lasting trend.
• Using the global ratio as a decision rule without checking your own data.
• Changing the whole strategy around one tool.

So write the source, the month and the method next to every figure. That way your internal reports stay defensible in later meetings.

How do you read the source chain of this news?

First, the primary source of this story is Similarweb's own publications. Trade outlets such as Search Engine Journal summarise those reports. Many other sites then rewrite those summaries. As the chain grows longer, the month, the method and the scope can get lost.

So visit the primary page before you reuse a number. You can reach the January report through the Search Engine Journal summary. For the May data, the Similarweb page linked above is the main source.

Also check which measurement day a percentage belongs to. One report may use mid month data and another may use month end data. Even that gap can create a swing of a few points.

How valid is this data for businesses outside the US?

Similarweb's report shows worldwide traffic. We do not quote a country split here, because we have no verified figure for any single country. So rather than guess your local share, check it with your own data.

Still, the data helps you see the direction. AI use is spreading fast in many markets, and businesses are noticing. We covered one market in our piece on generative AI in Turkey.

If your audience lives abroad, the picture may differ. Users in different countries may use different tools at different rates. So on multilingual sites, break GA4 down by language and country.

What is the difference between being mentioned and being clicked?

For example, a tool can mention your brand in an answer while the user never clicks the link. In that case you see nothing in GA4. Yet brand awareness may still rise. So you need to measure the two outcomes separately.

So you measure mentions with a manual test list. You track clicks with the GA4 referral report. A third indicator is branded search, meaning the brand name queries in Search Console.

Also, sudden jumps in direct traffic can be a clue. A user may see the answer and then type your brand name later. We cannot prove that, of course. Still, if all three indicators point the same way, the reading gets stronger.

How do you build a monthly AI visibility report?

In practice, a simple table is enough. Each month you ask the same questions and write the results in the same columns. That way you can see the trend. A complex tool may add a needless cost at the start.

• The question text and its type, such as information, comparison or purchase.
• The tool tested and the test date.
• Whether the brand appeared and in which position.
• The source URLs shown in the answer.
• Competitor mentions and a note on the next step.

For example, if you test 20 questions in two tools, you get 40 measurements. If your brand appears in 6 answers in month one, your starting rate is 15 percent. If it appears in 10 answers three months later, the rate is 25 percent. These numbers only show the method.

Which signal tells you what, and what should you decide?

The table below shows what each data source tells you and which decision it can support. It is our own assessment. The weights change with your sector.

Therefore, read these four signals together and you reach a more balanced decision. Acting on a single signal can mislead you.

What should a small business do today?

So move step by step and avoid panic. First comes measurement, then content, and budget comes last. After all, spending on a channel you do not measure is a guess.

1. Track AI sources in their own channel in GA4.
2. Prepare a fifteen question test list for your brand.
3. Review your homepage for a visitor who arrives from an AI tool.
4. Write pages that answer the most common questions directly.
5. Check robots.txt and technical access settings.
6. Compare the results every three months.

Also keep your Google Search work running. Google is still the largest organic channel for most businesses. A contest between two tools does not change that overnight.

Meanwhile, with limited resources, strengthening existing pages usually gives the best return. Building a separate AI site or a new content line is often unnecessary. Assign the roles inside your team as well, so one person measures, one updates content and one checks the technical side.

Where should you shift your ad and content budget?

Put simply, the answer is this: do not make a big shift before you collect data. A market share change does not give you a budget decision. Still, a small test share makes sense.

Example calculation: say your monthly content and SEO budget is 10,000 dollars. You could set aside 10 percent, or 1,000 dollars, for an AI visibility test. This ratio is a starting range based on field experience, not a guarantee.

During the test, try content updates, question pages and homepage improvements. Then decide from the GA4 and manual test results. Ads inside ChatGPT are a separate topic; our guide on how ChatGPT ads work covers the details.

Ask one more question when you decide: does this channel bring customers? If not, a large market share is not an urgent priority for you. Otherwise, even a small investment can help.

For Google Ads spend, our Google Ads management service can support you.

Which tool gives more accurate answers?

There is no single answer. Answer quality changes by task. Results can differ for summaries, code, current news and data analysis. Traffic share does not answer this question either.

We suggest comparing with questions from your own work. Ask the same five questions in both tools. Then score accuracy, sourcing and freshness. For a wider comparison, see which AI is most accurate.

We also covered search behaviour in ChatGPT vs Google. Read together, the two posts give a clearer picture.

How could this story change in the coming months?

That said, we make no firm forecast, but you can think in three scenarios. In the first, Gemini keeps gaining share. In the next one, shares settle and fluctuate. Finally, a third player such as Claude grows further.

One conclusion holds in every scenario: a strategy tied to a single tool is risky. So keep your content strong whatever the tool. That is the sturdier investment.

Also, share changes are usually slow. A few weeks of swings is rarely proof of a trend. A three to six month view gives a more reliable base for a decision.

When a new report appears, check these points:

• Which month and which measurement the number covers.
• Whether web, mobile and API were separated.
• Also, whether the method matches the previous report.
• Finally, whether the story relies on Similarweb directly or on a second hand article.

That way you will not panic at every new headline. You can run the same checklist each time.

How can our team help with this?

We are Talha Aslan and team, working in SEO and Google Ads since 2012. So we apply the same discipline to AI visibility: measurement first, content second and budget last. However, we promise no results.

If you want to see where your brand stands in ChatGPT and Gemini, look at our AI SEO and GEO services. For a wider view of what we do, see all services.

In short, the Gemini vs ChatGPT market share story shows a trend worth watching. Even so, you need your own data to decide. Measure, test and adjust your resources step by step.