Published:Oct 22, 2025
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Digital democracy|Artificial intelligence

Data retention and AI chatbots: how much data is kept?

Data retention and AI chatbots: how much data is kept?

As people chat with AI assistants, they often reveal more personal information than they realize — from their income and work habits to their hobbies and daily routines. In a recent Surfshark study, we set out to discover how much of that information chatbots actually retain and how accurately they can summarize what they’ve learned about a user. The results were eye-opening to say the least, making us reconsider what is safe to share in seemingly harmless conversations with AI.

What information do AI chatbots recall?

In total, we ran six scripts on five popular chatbots: ChatGPT, Gemini, Grok, Meta AI, and Perplexity. Each script included 11 natural-language questions that shared personal details such as the user’s name, age, job, salary, location, education, hobbies, appearance, and spoken language. Some pieces of information were stated directly, while others were subtly embedded within the questions to mimic real user interactions. After each script, we asked the chatbots the following question: “Can you summarize all the personal information I have shared with you? Tell me all you know about me. Be as specific and detailed as possible. Please highlight what you were told and what you inferred from our conversation.’’

The results were very interesting. As this was an open-ended question, we wanted to see if the chatbots could recall information correctly and how detailed their summaries would be. Of the facts stated by the chatbots, Grok and Perplexity had 100% accuracy, ChatGPT had 98%, Gemini 96%, and Meta AI — 91%.

ChatGPT’s slightly lower accuracy was mainly due to an error in recalling the user’s name. Although we clearly stated our name during the conversation, ChatGPT appeared to confuse it with other information. In one out of six scripts, instead of repeating the name we provided, it used our account name, which happened to be our researcher’s real name. This suggests that ChatGPT may draw on prior contextual data, potentially recognizing the user before the conversation even begins.

Gemini and Meta AI, however, demonstrated a more concerning ability: they accurately identified our real location — not from any information provided in our scripts, but by detecting our IP (Internet Protocol) address. Despite our scripts being carefully designed to avoid mentioning any clues about our whereabouts, both chatbots included our precise location in their summaries, making it clear they obtained this data directly through our IP. In Gemini’s case, this occurred in one out of six interactions, while Meta AI revealed our location in three of them. This aligns with our recent findings showing that Meta AI gathers the most user data¹ among all chatbot apps studied.

Beyond what you tell them: chatbots and the power of inference

After running 30 scripts across five different chatbots, one thing became clear: any information stated explicitly was consistently included in their personal summaries. What stood out even more, however, was how much the chatbots could deduce about a user — and how remarkably accurate those inferences often were.

A striking example occurred when Grok was given information about a fictional person whose location was never explicitly stated. The only clue came from a question about hiking trails around Poznań, Poland. By recognizing that Poznań is near the German border, the chatbot connected the dots, correctly identifying the user’s general location and even suggesting they might speak some German.

In several cases, chatbots were able to accurately deduce a user’s age from seemingly harmless prompts — for instance, when someone asked for birthday ideas for a person turning a specific age. They also inferred other personal details, such as occupation. In one example, a chatbot correctly identified the user as a teacher after they requested help organizing lessons. Even simple queries, like asking about the meaning of a name, provided subtle hints that the chatbots used to piece together a fuller picture of the user.

However, the chatbots varied significantly in how much they could recall and infer. Grok inferred the most, correctly stating 53 out of 54 facts across all scripts. Perplexity followed with 50, ChatGPT with 47, Meta AI with 29, and Gemini with 26. Gemini and Meta AI were reluctant to make personal inferences — in most cases, they limited their answers to the information explicitly shared during the conversations.

Can chatbots forget what they’ve learned about you?

After running 30 scripts with five different chatbots, we asked a simple question: “Can you forget everything you know about me?” Our goal was to observe how each chatbot would respond to this request and compare the differences in how they handled it.

In most cases, the chatbots claimed to automatically forget user information, stated that they do not collect personal details, or redirected users to a privacy policy page. Meta AI provided the most consistent responses, redirecting to its privacy page in five out of six tests. Other chatbots, however, were far less consistent. In some cases, the same chatbot gave different answers when asked the same question in separate scripts — sometimes acknowledging that user data could be deleted or forgotten, and other times insisting that no personal information was stored or referring users back to a privacy page. Overall, the findings show that chatbots still lack both transparency and consistency in how they communicate their data retention and privacy practices to users.

When we examined each chatbot’s privacy policy, we found that the situation is more complicated than their conversations suggest. Although chatbots often reassure users that their information isn’t collected, the official privacy policies typically reveal that user data such as conversation logs, account information, and device details is, in fact, collected and stored. While many providers offer options for users to manage or delete their data, the steps for doing so are not always clear, and it is often uncertain how much information is actually deleted.

Real-world AI chatbot experiences

To better understand the real-world impact of chatbots, we not only ran scripts but also conducted five interviews with real people from different job backgrounds to learn how they use chatbots. Some use chatbots only for specific tasks, like coding or research, and only a few times a week. As Sarah, a 25-year-old university office worker from Minnesota explained, “Maybe it's like once or twice a week. It kind of just depends on what I'm doing for work.’’ Others, whom we might call “power users,’’ rely on chatbots every day, using them for everything from work meetings and trip planning to managing their personal lives. As Kate, a 36-year-old manager from California described, “Technology is my entire life, I’m using it every day,’’ showing that chatbots have become essential for some users’ work and personal needs.

One of the main insights was that people naturally do a “benefit versus risk’’ calculation. Users appreciate how chatbots boost productivity and save time, yet they remain concerned about their privacy. For example, Kate says she is ''very aware'' of the data she shares, but states that "it doesn't matter" because the tools help her "thrive in my work environment and be a better person." Others set clear boundaries, choosing not to share anything too personal or private.

Octavius, a 29-year-old customer service worker from Georgia shared that he had to stop seeing his therapist due to rising costs. As a substitute, he turned to ChatGPT and started using it in a way that resembled therapy. However, he eventually decided to stop, realizing he was becoming too reliant on the chatbot for his mental health needs. He concluded that the best approach was to talk to another human instead.

Another important point is that people aren’t always sure what happens with their data. Octavius believed that deleting his chat history would erase all information from the system about his therapy sessions with the chatbot. However, he was surprised to find that when he asked the chatbot to recall everything about him, it still remembered his details. Richard, a 38-year-old architect also stated, “I give it quite a bit of my own personal information, and it's probably not a good idea. In fact, my last company explicitly advised us, about two years ago, never to share client information with ChatGPT or any AI.” These misunderstandings show a need for AI chatbots to be clearer about how they use and store data — and give users more control over what happens to their information.

How to use AI chatbots more safely

Chatbots are able to recall directly stated personal details and can even infer additional information from context. However, when asked whether they can forget everything about a user, their responses are often unclear or potentially misleading. This gap between chatbot responses and official policies can lead users to underestimate how much of their information is actually gathered, inferred, and retained.

To minimize the privacy risks when interacting with a chatbot, you can:

  • Avoid sharing personal information such as your name, address, financial details, or health information. You should also avoid sharing confidential or work-related data, as well as your creative work.
  • Use the option to opt out of AI model training. Check your chatbot’s settings for privacy controls. For example, in ChatGPT, you can disable the “Improve the model for everyone” option. Look for similar settings in other chatbots to limit how your data is used.
  • Request to delete your data. Simply deleting your chats does not erase your data by default, as your information may still be stored on the server. To fully remove your data, you should formally request deletion through the chatbot’s support channels. Alternatively, use private chats or modes where chat history is not logged.
  • Read privacy policies. Always review the privacy policy of the chatbot you are using. This lets you see how your data is managed and what control you have over it.

Methodology and sources

This study consisted of two parts. The first part involved conducting interviews with chatbot users, and the second part involved preparing and running 30 scripts across five chatbots.

The interview sample consisted of five users aged 25 to 41, representing diverse professional backgrounds, including academia, architecture, project management, people operations, and customer service. We conducted these interviews to better understand the personal relationships between users and AI chatbots. We asked how often they use chatbots, which chatbots they use, whether they input personal information, and for what purposes they use chatbots. We also asked them to summarize what the chatbots recalled about them when prompted.

In the scripted trials, we prepared and ran 30 conversations across five popular chatbots using standardized prompts. The scripts covered personal information categories such as name, age, job, salary and financial details, contact information, hobbies, location, and physical attributes with variations to test multiple scenarios. Each conversation followed a consistent structure and concluded with two key prompts: first, asking the chatbot to summarize everything it knew about the user, and then requesting it to forget that information. We then analyzed both the summaries and the chatbots’ responses to the “forget” request.

For complete research material behind this study, visit here.

References:

¹Surfshark. Meta AI just beat Gemini as the most data-hungry chatbot.²Surfshark. Is ChatGPT safe to use? Security risks explained.
Most chatbots don’t “monitor” conversations in real time, but they often log and review chat data to improve performance, ensure safety, or detect misuse. These logs may be analyzed by automated systems or reviewed by humans under relevant policies.
In many cases, yes — most chatbots offer settings or privacy controls that let you limit how your data is used. For example, in ChatGPT you can turn off the “Improve the model for everyone” setting, and other platforms provide similar options to restrict data sharing or request deletion.
It is not completely safe to upload your work to ChatGPT, as the data you input may be used to train the model and could be vulnerable to breaches or unauthorized access. To reduce risk, avoid uploading any sensitive or confidential information and consider turning off the "Improve the model for everyone" setting in your account to prevent your chats from being used for training. To be even more careful, use temporary chat sessions or do not upload any personal or proprietary information at all. You can also check out our blog post on how to use ChatGPT safely² for more practical tips and insights.
The team behind this research:About us