How Grok, ChatGPT, Claude, Perplexity, and Gemini Handle Your Data for AI Training (2025 Guide)

Artificial intelligence assistants have exploded in popularity. From ChatGPT and Claude to Grok, Perplexity, and Google’s Gemini, these tools are now part of our everyday lives. They write our emails, summarize articles, brainstorm ideas, generate code, and even help with research.

But there’s a big question many users are asking:

👉 What happens to my data when I use these AI tools?

Do companies save your prompts? Do they use them to train future models? And most importantly—can you stop them from doing so?

If you’d like to dive deeper into how each AI platform works individually, we’ve prepared dedicated guides. You can explore our detailed breakdown of Grok AI chatbot and how it integrates with X, or read our complete review of ChatGPT to understand OpenAI’s most popular tool. For those interested in Anthropic’s approach, our article on Claude AI covers its unique training policies. We also reviewed Perplexity AI to explain its search-driven model, and you can check out our guide to Google Gemini AI to see how Google is competing in the AI race.

In this article, we’ll dive deep into how Grok, ChatGPT, Claude, Perplexity, and Gemini handle your data in 2025. We’ll explore:

• Which platforms automatically use your chats for AI training
• What privacy controls and opt-outs are available
• Major privacy incidents and lawsuits tied to these companies
• A side-by-side comparison table to make things simple

By the end, you’ll know exactly how each tool treats your data—and what steps you can take to protect your privacy.

1. Grok (xAI / Elon Musk)

How Grok Uses Your Data

Grok is tightly integrated with X (formerly Twitter). When you use it, your public posts, replies, and even your chats with Grok may be collected and used for training and fine-tuning xAI’s models.

This happens by default unless you opt out.

Privacy Controls & Opt-Out

You can opt out through your X account settings:

1. Go to Privacy & Safety
2. Find Data Sharing & Personalization
3. Toggle off the setting under “Allow your data to be used for training and fine-tuning”

Privacy Incidents

In August 2025, Grok suffered a major privacy disaster. Over 370,000 user chats were accidentally indexed by Google Search, exposing private queries to the public. This event raised huge concerns about how xAI handles user safety.

👉 Lesson: Even if you opt out, accidents and leaks can still put your data at risk.

2. ChatGPT (OpenAI)

How ChatGPT Uses Your Data

OpenAI’s policies differ based on whether you’re a free or paid user:

• Free Users: By default, your prompts may be used to improve the model.
• ChatGPT Plus & Enterprise Users: Enterprise data is not used for training, and enterprise contracts guarantee stronger protections.

Privacy Controls

• You can disable chat history. When history is off, your conversations aren’t saved or used for training.
• You can delete past chats from your account settings.
• OpenAI offers data export tools so you can see exactly what’s stored.

Notable Privacy Concerns

OpenAI has not faced a Grok-level data leak, but critics often highlight the unclear consent for free users. If you use the free tier, assume your data may contribute to training.

3. Claude (Anthropic)

New Data Policy (2025 Update)

Anthropic made headlines in August 2025 when it changed Claude’s data usage rules:

• Your chats are now retained for up to five years
• They may be used to train models
• This is the default setting unless you opt out

Mandatory Opt-In/Out

When you next open Claude, you’ll see a pop-up:

• Big “Accept” button = opts you into training
• Small toggle = lets you opt out

If you ignore the choice, you lose access to Claude after September 28, 2025.

Limitations

• Only new chats are affected (not old, deleted ones)
• Opt-out is not retroactive—if you already agreed, past data can’t be removed
• Anthropic claims it filters sensitive data and doesn’t sell your chats

Legal Pressure

Anthropic is currently:

• Facing a lawsuit from Reddit for allegedly scraping user content without permission
• Settling lawsuits with authors over using copyrighted books in AI training

👉 Claude’s new data policy is one of the strictest in forcing users to “choose”—but many criticize the lack of true user control.

4. Perplexity AI

How Perplexity Uses Data

Perplexity positions itself as a transparent AI search engine, often citing sources directly. Its data handling depends on the type of user:

• Enterprise Customers: Data is never used for training
• API Users: Follow a Zero Data Retention policy (inputs not stored or used)
• Regular Users: By default, some data may be used—but you can opt out

Key Detail

If you opt out, future chats won’t be used. But any data already processed will remain in the system.

Legal Issues

Perplexity has faced multiple copyright lawsuits in 2025:

• Sued by Japanese publishers (Nikkei, Asahi Shimbun)
• Targeted by NYT and other US outlets for content scraping

To respond, Perplexity launched “Comet Plus” ($5/month), which shares 80% of revenue with publishers.

5. Gemini (Google DeepMind)

Data Policy for Gemini Apps

When you use Gemini in consumer apps (mobile, web), Google gives you granular privacy settings to control:

• Whether your activity is saved
• Whether your chats are used for training
• Personalized AI recommendations

Gemini in Google Cloud

For business users, Google makes it clear:

• Prompts and responses are not used to train models
• Enterprise agreements include confidentiality protections

Gemini API

When using Gemini via API:

• Inputs/outputs may be reviewed by humans
• However, the data is anonymized and not tied to your account
• Sensitive info should never be submitted

Privacy Strength

Compared to Grok and Claude, Google offers stronger user choice—but its business model still revolves around data collection across its ecosystem, so caution is warranted.

Comparison Table

Practical Tips to Protect Your Data

1. Always review AI app settings after updates—policies change often.
2. Opt out of training if privacy matters to you.
3. Avoid entering sensitive data (passwords, financial details, private docs).
4. Consider enterprise versions if you use AI for business-critical work.
5. Stay updated—new lawsuits, leaks, and scandals reshape policies regularly.

FAQs

1. Can I stop AI companies from using my chats?

Yes, most tools provide opt-out options—but not all are retroactive.

2. Which AI tool has the best privacy?

For enterprise use, Gemini (Google Cloud) and Perplexity offer the strongest guarantees.

3. What happens if I do nothing?

In tools like Claude or Grok, doing nothing often means you are opted in by default.

4. Should I trust AI with sensitive business data?

Not unless you’re using the enterprise version of a platform with legal protections.

Final Verdict

The way AI companies handle your data in 2025 is a balancing act between innovation and privacy:

• Grok is risky—data collection is broad and a major leak already occurred.
• ChatGPT offers better controls, especially for enterprise users.
• Claude is controversial—forcing users to choose between sharing data or losing access.
• Perplexity takes transparency seriously but faces copyright lawsuits.
• Gemini provides strong enterprise protections and granular consumer controls.

At the end of the day, the choice is yours. If you value privacy, take a few minutes today to opt out where possible—and remember, never share data in AI chats that you wouldn’t want exposed.