Privacy-First AI APIs: Which Ones Don't Train on Your Data

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Five AI APIs do not train on your prompts or outputs by default: the Anthropic Claude API, Azure OpenAI (Microsoft calls the hosted OpenAI models "Models sold by Azure"), Google Vertex AI, the OpenAI API, and Amazon Bedrock. Each publishes a data processing addendum (DPA). They differ on how long data is kept, whether processing can stay in the EU, and how much notice you get before a new sub-processor sees your data.

Updated October 24, 2026: We added a table of zero data retention (ZDR), human review, and training opt-out terms for each API plan, with a link to the provider page behind every cell. We also re-checked the rest of this guide. Google's Vertex AI documentation now uses the name Gemini Enterprise Agent Platform and lists durable caching as on by default for supported Gemini models. xAI's enterprise FAQ now names the company SpaceXAI LLC. Two earlier statements were wrong; see the correction at the end.

Updated October 8, 2026: We re-checked every provider against its own documentation. Mistral moved out of the top five because its API can use data for improvement until an admin turns that off, and Amazon Bedrock moved in. OpenAI now offers Europe data residency. Several retention figures in the old version (OpenAI, Azure, Vertex, and Bedrock as "0 days") were wrong and are corrected below.

TL;DR: A privacy-first AI API does not train on your prompts by default, gives you a DPA, and tells you how long it keeps your data. Five providers meet the first two tests by default: Claude API, Azure OpenAI, Vertex AI, OpenAI API, and Amazon Bedrock. None of them keeps zero data by default; all five offer a zero data retention path on stated terms.

Consumer apps are a different contract. Claude Free, Pro, and Max users choose whether their chats are used for training, and chats kept for training are retained for five years. ChatGPT personal-account chats can be used for training while the "Improve the model for everyone" setting is on; turn it off and new conversations are not used. Google AI Studio and the unpaid Gemini API quota are "Unpaid Services": Google uses that content to improve its products, and human reviewers may read it. The exception is users in the European Economic Area, Switzerland, and the UK: Google applies its paid-service data terms to them even on unpaid use.

When your team sends prompts to an AI API, you are the data controller and the provider is your processor. GDPR applies as soon as a prompt contains information about an identifiable person. The question is not only whether the provider trains on your data. It is whether you have the right contract, the right settings, and data hygiene in your prompts.

This guide covers: how each major API handles training and retention • ZDR, human review, and training opt-out by API plan • the sub-processor notice each DPA gives you • the three contract clauses that matter • CCPA service provider basics • a copy-paste DPA request email • a 10-item DPA checklist • what never to put in a prompt.

Which AI APIs Do Not Train on Your Data by Default

The table below adds the providers outside the top five. Rows marked "not verified" are ones where we could not find a current statement in the provider's own documentation; treat them as unknown until the vendor confirms in writing.

We dropped AI21 Labs, Perplexity, Together AI, Replicate, and Hugging Face from this table in October 2026: we could not open a current data-use statement for their APIs, and we do not publish a "yes" or "no" we cannot source.

The API and the consumer app from the same company are different compliance positions. A developer calling the Claude API is covered by the Commercial Terms; an employee pasting the same text into a personal Claude.ai account is not.

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Anthropic Claude API

Anthropic says it will not use inputs or outputs from its commercial products, including the API, to train models by default. If someone in your organization sends feedback with the thumbs up or down button, the related conversation can be stored for up to 5 years and used for training. API inputs and outputs are deleted within 30 days of receipt or generation, unless you use a feature with longer retention (such as the Files API), you have a zero data retention agreement, or content is flagged for a Usage Policy violation (inputs and outputs then kept up to 2 years). Since June 9, 2026, Anthropic's Covered Models (Claude Mythos 5 and 5.1, Claude Fable 5 and 5.1) need 30-day retention on every platform that offers them, so they are not available under zero data retention unless Anthropic expressly authorizes it.

GDPR note: the Anthropic DPA is incorporated into the Commercial Terms, and the SCCs (Module Two and Module Three) are incorporated by reference. We did not find an EU-only processing option in Anthropic's documentation: the inference_geo setting offers "global" (the default) or "us".

Azure OpenAI

Microsoft states that prompts, completions, embeddings, and training data are not available to OpenAI and are not used to train any generative AI foundation models without your permission or instruction. Azure runs abuse monitoring: content flagged as harmful can be reviewed by automated systems and, in some cases, by authorized Microsoft employees (located in the EEA for EU deployments). Customers with sensitive use cases can apply for modified abuse monitoring, which turns off human review. For EU DataZone deployments, prompts and responses may be processed in any EU member state.

OpenAI API

OpenAI says that as of March 1, 2023, data sent to the API is not used to train or improve its models unless you opt in. Abuse monitoring logs are generated for all API usage and kept for up to 30 days. Eligible customers can have content excluded from those logs (zero data retention). OpenAI now offers data residency for eligible customers, including a Europe (EEA + Switzerland) region reached through eu.api.openai.com; models released on or after March 5, 2026 carry a 10% price uplift on data residency endpoints. OpenAI's published sub-processors include Microsoft, CoreWeave, Oracle Cloud Infrastructure, and Google Cloud Platform.

Google Vertex AI

Google's training restriction says it won't use your data to train or fine-tune any AI/ML models without your prior permission or instruction. Google's documentation now files Vertex AI's generative AI pages under the name Gemini Enterprise Agent Platform. By default, supported Gemini models cache your data in memory and, when memory runs out, in durable storage at rest; both caches are deleted no later than 24 hours after they are written and are never used for training. You can turn off durable caching per project, or turn off caching entirely. Google may also log prompts for abuse monitoring under its terms, so zero data retention requires specific steps that Google lists in its documentation. EU regions include Belgium (europe-west1), Netherlands (europe-west4), Frankfurt (europe-west3), and Finland (europe-north1).

Amazon Bedrock

AWS says Bedrock content "is not used to improve the base models and is not shared with any model providers." Model providers have no access to Bedrock logs or customer prompts. Retention depends on the model unless you set the zero data retention mode, in which no request or response data is written to durable storage. Bedrock Guardrails also include sensitive information filters that can remove PII from conversations.

Mistral API: EU-hosted, but check one toggle

Mistral says data is hosted in the European Union by default, unless you call its US endpoint. Some features can transfer data outside the EU; Mistral says those transfers use the European Commission's Standard Contractual Clauses. On training, Mistral's help center says Studio and API customers can opt out of data training at any time through the Admin panel, under Privacy, by disabling the "Anonymous improvement data" toggle. Free mode data may be used for training. Zero data retention is available only on pay-as-you-go and only for stateless API calls.

If EU hosting is your main requirement, Mistral is still a strong option, but make turning off that toggle part of your setup, not an assumption.

ZDR, Human Review, and Training Opt-Out by API Plan

Zero data retention (ZDR) means the provider keeps no prompts or outputs once it has returned the response. Human review means the provider's staff or contractors can read your prompts, usually after an abuse classifier flags them. The opt-out column tells you whether there is anything to switch off. We read every linked page on October 24, 2026. Where the provider's own pages say nothing, the cell says "not stated".

Cohere's commitments cover paying SaaS customers, which Cohere defines as accounts with a credit card on file; trial keys fall under its Terms of Use and Privacy Policy, which we did not check. On private deployments and third-party cloud platforms, Cohere says it does not receive prompts or outputs at all.

If the deciding question is whether a person at the provider can read a flagged prompt, the documents give a clear "no" in only a few setups: Azure with modified abuse monitoring, Vertex AI for Google models under a Cloud Master Agreement, and Bedrock outside aws_review mode (AWS still checks image inputs and outputs for child sexual abuse material). Anthropic's standard API, Mistral, and Groq don't say either way, so ask in writing before you send privileged, health, or HR data.

Data Retention by Provider

The old version of this table listed OpenAI, Azure, Vertex, and Bedrock as keeping data for "0 days" by default. None of the providers' current documentation says that.

Sub-Processor Notice: How Much Warning You Get

Under GDPR Article 28(2), a processor shall not engage another processor without the controller's prior specific or general written authorisation. With general authorisation, the DPA sets how you hear about new sub-processors and how long you have to object.

Subscribe to each provider's sub-processor notices. When a new sub-processor appears in a country without an EU adequacy decision, that is a change to your transfer assessment.

How to Check Your Settings

These are the controls each provider documents. Menu names change, so search the provider's docs if a label has moved.

• Anthropic: commercial API data is not used for training by default. If you need zero data retention, it is an agreement, not a toggle. Team and Enterprise owners can disable feedback submission for members.
• OpenAI API: confirm whether your organization is approved for zero data retention, and, if you need EU processing, whether your project uses data residency (eu.api.openai.com).
• Azure OpenAI: for highly sensitive data, apply for modified abuse monitoring. Pick an EU DataZone deployment if processing must stay in the EU.
• Google Vertex AI: turn off durable caching, or all caching, for the project if your policy requires it, and follow Google's zero data retention steps. Use Vertex under your Google Cloud account, not AI Studio with a personal account.
• Amazon Bedrock: set the data retention mode to none for zero data retention on supported models, and consider Guardrails sensitive information filters.
• Mistral: in the Admin panel, under Privacy, disable "Anonymous improvement data." The Vibe and API toggles are separate.

The Three Contract Clauses That Matter

When reviewing any AI API agreement for GDPR or CCPA, look for these three clauses.

1. No secondary use for training

The agreement should say the provider will not use your data to train, improve, or develop AI models, including fine-tuning and evaluation. Generic phrases like "we may use data to improve services" are not enough. Watch for carve-outs: Anthropic's and Mistral's feedback buttons, for example, let a single click send a conversation into training.

Example clause: "Provider will not use Customer Data to train, retrain, fine-tune, or improve foundation models."

2. Sub-processor list and notification

The agreement should include a sub-processor list (or a link to one) and a notice or objection period. Among the DPAs above, OpenAI, Google, and AWS work with 30-day windows; Anthropic gives 15 days to object and Mistral 10.

Example clause: "Provider will notify Customer at least 30 days before adding new sub-processors."

3. Deletion on request and at termination

You must be able to delete your data. The agreement should commit to deletion on request and at termination. Mistral's DPA, for example, says personal data is no longer accessible 30 days after your access ends.

Example clause: "Provider will delete or return all Customer Data within 30 days of termination."

CCPA: Service Provider Basics

Under CCPA, a vendor that processes personal information on your behalf is usually a service provider, not a buyer of the data. The California Attorney General's CCPA page uses the example of a retailer that contracts with a payment card processor, and notes that "The CCPA treats service providers differently than the businesses they serve." In practice:

1. Make sure the contract you accepted covers the API product, not a consumer app.
2. Check that the vendor may use the data only to provide the service.
3. Keep consumer request handling with your business; a service provider may refuse to act on requests sent to it directly.

DPA Request Email Template (Copy-Paste Ready)

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Send this to your AI API vendor's sales or legal contact before you commit to any plan involving personal data. Replace the bracketed fields.

Subject: Data Processing Agreement Request, [Your Company Name]

Hello,

We are evaluating [Provider Name] API for use in our [describe use case: e.g., customer support automation / internal document processing / HR workflow].

Before we proceed, we need to confirm our data processing arrangements under GDPR and [CCPA / applicable state privacy law].

Please provide the following:

1. Data Processing Agreement (DPA) including:
   - Confirmation that you will not use our data to train, fine-tune, or improve AI models
   - Sub-processor list with names and locations
   - Data retention period and deletion timeline on request and at termination
   - EU Standard Contractual Clauses (if you process outside the EU) or equivalent transfer mechanism

2. Confirmation that our plan tier includes the DPA (some providers only offer DPAs on enterprise plans)

3. Your data residency options, specifically whether we can restrict processing to EU-based infrastructure

4. Zero-retention or short-retention options, whether we can reduce the standard retention window

We process data about [EU residents / California residents / employees / customers, describe your situation]. Our planned go-live is [date].

Please send the DPA and any related documentation to [your email], or direct us to your self-serve DPA process if available.

Thank you,
[Your name]
[Title]
[Company]

Where to find the published DPAs:

• Anthropic: anthropic.com/legal/data-processing-addendum
• OpenAI: openai.com/policies/data-processing-addendum
• Microsoft: Microsoft Products and Services DPA
• Google Cloud: cloud.google.com/terms/data-processing-addendum
• Mistral: legal.mistral.ai/terms/data-processing-addendum

DPA Checklist for AI APIs

Before sending personal data to any AI API:

• DPA in place and covering the product you use (not just a consumer Terms of Service)
• DPA includes EU Standard Contractual Clauses if the provider processes outside the EU
• Sub-processor list reviewed and notice period understood
• Default retention period confirmed, and zero data retention requested if you need it
• Deletion on request and at termination confirmed in writing
• Training default confirmed in the provider's docs, and any opt-out toggle turned off
• Data minimization: are you sending only what the API needs?
• Special-category data excluded from prompts (health, biometric, political, etc.)
• CCPA service provider terms in place if California residents are in scope
• Internal record of processing activities (ROPA) updated to include this provider

What Data Should Never Go into Any AI API Prompt

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Regardless of which provider you use or how good their DPA is, keep these out by default:

• Social Security numbers or national ID numbers
• Payment card numbers (PCI scope, a separate obligation)
• Special-category data under GDPR Article 9: racial or ethnic origin, political opinions, religious beliefs, trade union membership, genetic data, biometric data used to identify someone, health data, sex life or sexual orientation
• Children's data: GDPR Article 8 sets 16 as the default age for consent to online services, and member states may lower it to no less than 13

Handle with caution:

• Full names combined with email addresses or job titles (identifiable)
• IP addresses in system prompts (personal data under GDPR)
• Employee performance data
• Legal advice or attorney-client privileged material

The safest prompt practice: replace personal identifiers with tokens before sending to the API, and map them back after the response comes back.

What Developers Say

In a January 2026 r/gdpr thread, "Current state of OpenAI/Anthropic API compliance for EU healthcare?", one regular argued that the contract is the solved part: "Using AI services is not fundamentally different from a Microsoft 365 subscription." The harder questions, in that commenter's words, are that "key GDPR challenges relate to risk assessments" and to accuracy. When another commenter suggested EU-only or self-hosted models, the person who asked the question replied: "Sounds good in theory, but the cloud models are so much better in some ways."

That trade-off is the real decision: the DPA and the training default rarely separate these providers any more; location, retention, and your own risk assessment do.

Our take

Based on the providers' own documentation above, "doesn't train on your data" is now the easy part: all five main providers say so by default. The differences that actually decide a vendor are retention, human review, and location. If you need data to stay in the EU, OpenAI's Europe residency and Azure's EU DataZone are now real options alongside Mistral, but Mistral needs its improvement toggle turned off and Anthropic does not document an EU-only option. If you need zero retention, plan for an application, an agreement, or a setting you change yourself (Bedrock and Groq), not a default, and check that the model you want is eligible: Anthropic's Covered Models are not. And read the feedback-button terms: one thumbs-up in Anthropic's or Mistral's products can send a conversation into training even when the account is opted out.

How we checked this

On October 8, 2026 we opened each provider's own pages (Anthropic Privacy Center and DPA, OpenAI platform docs, help center, DPA and sub-processor list, Microsoft Learn, Google Cloud docs and the Cloud DPA, AWS Bedrock docs, FAQ and DPA, Mistral's help center and DPA, the xAI enterprise FAQ, Groq and Cohere pages, Google's Gemini API terms) plus GDPR on EUR-Lex and the California Attorney General's CCPA page. We corrected the training status of Mistral, xAI, and Claude consumer plans, the retention figures for four providers, OpenAI's EU hosting status, five sub-processor notice periods, and three dead DPA links. We removed a "2026 provider updates" section and a 1-to-5 score table whose claims we could not source, and five vendor rows we could not verify.

On October 24, 2026 we re-opened every provider page cited above and compared each quote in our source log with the live text, then read the ZDR, abuse monitoring, and data commitment pages behind the new plan table: Anthropic's API data retention docs and Covered Models article, OpenAI's enterprise privacy page, Azure's abuse monitoring page, Google's Agent Platform ZDR and abuse monitoring pages, the Gemini API ZDR and abuse monitoring pages, Bedrock's data retention and abuse detection pages, Mistral's ZDR article and privacy policy, Groq's data page, and Cohere's enterprise data commitments.

Correction (October 24, 2026): The October 8 version said Google uses Google AI Studio and unpaid Gemini API content to improve its products, without the exception in Google's terms: for users in the European Economic Area, Switzerland, and the UK, the paid-service data terms apply to those services too. The retention table also listed Anthropic's zero data retention as available "by agreement" without noting that Covered Models (Claude Mythos 5 and 5.1, Claude Fable 5 and 5.1) have required 30-day retention since June 9, 2026. The provider table marked Cohere's DPA as not verified, but Cohere's enterprise data commitments page tells SaaS customers to email [email protected] for one. All three are fixed above.

Last reviewed: October 24, 2026.

Check your provider's DPA directly; terms change.

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