Your AI Chat History: When to Keep It and When to Delete It

Updated June 21, 2026

A Midjourney user deleted their account in January 2025. Three months later, they Googled their own username and found dozens of their "deleted" images still indexed — thumbnails cached by Google, linked back to Midjourney's public gallery. The images had been removed from the user's dashboard,, but the public URLs never died. That's not a bug. That's the default. (per Midjourney's Terms of Service, which reserves the right to retain content on its servers indefinitely)

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We pulled the privacy policies for seven AI tools you probably use every day. Most of them keep your data for years. Some keep it forever. And deleting your account doesn't always fix it. Here's what each tool actually collects — and the one setting change that closes the biggest gap.

Quick Answers: Data Retention Basics

Most AI tools keep user data for years unless you change settings. ChatGPT saves all conversations forever by default. Gemini keeps chatting history up to 18 months by default, with options to extend to 36 months or shorten to 3 months (Google Account Help). Midjourney images stay public unless you pay for Stealth Mode on the Pro ($60/month) or Mega ($120/month) plan (Midjourney pricing).

Free tiers are the worst offenders. Perplexity's free plan retains every query you've ever typed, with no expiration date and no bulk-delete option. Claude's free tier defaults to allowing Anthropic to use your conversations for model improvement, and that data may be retained for an extended period under Anthropic's privacy policy. Upgrading to a paid plan doesn't erase what's already been collected, but it does unlock opt-out controls that free users don't get — All ChatGPT users — including free-tier accounts — can toggle off training data contributions via Settings → Data Controls → 'Improve the model for everyone.' This is not a Plus-only feature., and Claude Pro gives you a clearer opt-out path to limit data retention.

Then there's the cloud provider question. Every tool on this list — every single one — stores your data on infrastructure owned by Amazon, Google, or Microsoft. That's standard for any SaaS product, but it means your prompts aren't sitting on some startup's laptop. They're distributed across enterprise cloud systems with their own retention and compliance rules.

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That cloud dependency matters most for the tools with the weakest user-facing controls.

The Dead Data Problem: What Survives After Deletion

Deleting your account doesn't always mean deleting your data. ChatGPT retains certain data in backups for up to 30 days after account deletion, per OpenAI's privacy policy. Deleting individual conversations removes them from your view but they may remain in system backups on a shorter cycle., and some data may persist longer after full account deletion (OpenAI privacy policy). Midjourney's public gallery URLs can persist in search engine caches long after you've removed the images from your dashboard. Grammarly processes text in supported input fields — documents, emails, and form fields — while its extension is active, including drafts you never send. It does not capture keystrokes outside of supported text contexts (passwords, terminal input, unsupported apps). — and retains that data for "product improvement" with no stated expiration.

The gap between "I deleted it" and "it's actually gone" ranges from approximately 30 days (Claude, if you've opted out of training) to essentially forever (Midjourney images that were publicly indexed before deletion).

Data Retention Timelines: A Side-by-Side Comparison

ChatGPT's "forever" default means OpenAI holds every conversation you've had since you created your account — potentially years of prompts. The one setting to change: go to Settings → Data Controls → toggle off "Improve the model for everyone." This stops future conversations from entering the training pipeline, though it won't retroactively remove what's already been collected.

Gemini's 18-month default is better than most, but here's the catch: deleting your Gemini chat history doesn't touch your YouTube watch history, Gmail data, or Google Search activity that's linked to the same account. Change your auto-delete to 3 months under My Google Activity → Web & App Activity.

Claude gives you the cleanest binary choice. During setup (or in settings later), you pick either "help improve Claude" (extended retention for training) or opt out (data deleted on a shorter timeline). If you're on the free tier, you're opted in by default. The setting is under Settings → Privacy — flip it to opt out.

Copilot is the odd one out for enterprise users. Microsoft explicitly states it won't use organizational data (emails, documents, Teams chats) for model training. But personal Copilot usage on Bing still logs prompts indefinitely. If you're using Copilot at work, your IT admin controls retention. If you're using it at home, you're on your own.

Perplexity retains free-tier queries forever with no user-accessible purge. Enterprise customers can enforce custom retention windows, including zero-retention configurations. For individual users, the only move is manually deleting threads one by one — there's no "delete all" button.

Midjourney makes every generated image public by default. Other users can view, rank, and remix your creations. Stealth Mode — which hides your images from the public gallery — requires the Pro plan ($60/month) or Mega plan ($120/month). Even with Stealth Mode, images you generated before upgrading stay public unless you delete them individually.

Grammarly processes text passively — every email draft, Slack message, and Google Doc you type while the extension is active. Go to Grammarly Account → Privacy → toggle off "Product Improvement" to stop your keystrokes from feeding their models.

AI Privacy Audit: The Three Gaps Nobody Advertises

Incidental Sensitive Data

Paste your AWS API key into ChatGPT once — even accidentally — and it lives on OpenAI's servers until you manually find and delete that specific conversation. There's no automatic scrubbing for sensitive data. A Harmonic Security analysis of enterprise AI prompts reported that roughly 35% contained sensitive information, from API keys to internal financial data (Harmonic Security, 2024). That's not careless employees. That's a design problem — these tools make it frictionless to share sensitive context, and nearly impossible to claw it back.

Third-Party Sub-Processors

Your data doesn't just sit with the AI company. It passes through cloud providers with their own data handling practices. Grammarly explicitly states its data is processed through AWS servers. OpenAI runs its infrastructure primarily on Microsoft Azure, under the terms of Microsoft's multi-billion-dollar investment partnership. AWS is not a primary infrastructure provider for OpenAI.. When you read a privacy policy that says "we don't share your data with third parties," check the fine print — cloud infrastructure providers are almost always exempted from that promise.

Mobile App Permissions

AI tools on mobile collect more than their web counterparts. Camera access, GPS data, contact lists — permissions that have nothing to do with generating text or images. Midjourney's mobile app requires full internet permissions. ChatGPT's mobile app can access your photo library, microphone, and location. Before installing any AI tool's mobile app, ask yourself whether you actually need it on your phone, or whether the browser version does the same job with fewer permissions.

How to Protect Your Data

Opt out of training immediately. ChatGPT: Settings → Data Controls → toggle off model improvement. Claude: Settings → Privacy → opt out. Grammarly: Account → Privacy → disable Product Improvement. Do this today — it takes under two minutes per tool.

Use enterprise plans if your employer offers them. Perplexity's enterprise API and Copilot for Microsoft 365 both offer zero-retention options that consumer plans don't. If you're pasting work documents into AI tools on a free plan, you're creating a compliance liability.

Audit your history quarterly. Scroll through your ChatGPT conversations and delete anything containing credentials, financial data, or personal information. Same for Perplexity threads and Gemini chats. If you wouldn't email it to a stranger, don't leave it sitting in an AI tool's database.

Think twice before installing mobile apps. The browser versions of ChatGPT, Claude, and Perplexity work fine. You don't need to give these companies access to your camera roll and GPS coordinates.

Final Takeaway

Open your ChatGPT settings right now. Toggle off chat history for training. Then scroll through and delete any conversation where you pasted something sensitive — an API key, a salary number, a medical question. That takes 90 seconds. And it closes the single biggest privacy gap most people leave wide open. The default settings on these tools are built for the company's benefit, not yours. Change them.

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Found an error? At Canopy Press, accuracy comes first. If you spot a claim that needs checking, let us know at [email protected] — we'll verify and correct it immediately.

Sources

• Securities and Exchange Commission
• Social Security Administration