- On October 15, 2026, 404 Media reported that advertisers can target ChatGPT users by uploading email addresses and phone numbers, which OpenAI matches against ChatGPT accounts, alongside targeting based on what people type. OpenAI's help pages confirm the uploads, which it calls custom audiences.
- OpenAI's docs accept raw or SHA-256-hashed emails and phone numbers, plus Google Advertising IDs. Targeting a list requires at least 25,000 matched users; excluding a list has no minimum. OpenAI says uploaded files are usually deleted within 24 hours and that advertisers can't see who matched.
- Turning off ad personalization still leaves ads based on your current chat. OpenAI's user help page doesn't mention advertiser lists, and none of its pages checked October 18 says whether the setting stops list matching. Only Free and Go users see ads.
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How are ChatGPT ads targeted? On October 15, 2026, 404 Media's Joseph Cox reported that advertisers can aim ads in ChatGPT at specific groups of people. They can use the prompts people type, and they can upload customer lists of email addresses and phone numbers, which OpenAI matches against ChatGPT accounts. OpenAI's own help pages and developer docs confirm the list-upload feature, which OpenAI calls custom audiences. The page OpenAI points users to about ads doesn't mention it.
This story is based on 404 Media's report (most of it is paywalled, so details come from its free sections and from MobileSyrup's and Gadget Review's write-ups of it), OpenAI's Help Center and Ads developer docs, OpenAI's privacy policy (updated September 10, 2026) and its Privacy Center, checked October 18, 2026.
The short version
- Three things can pick the ad you see: what you're chatting about now; your past chats, memory and ad activity, if ad personalization is on; and lists that advertisers upload.
- What advertisers can upload: email addresses and phone numbers, raw or SHA-256 hashed, and Google Advertising IDs from Android phones.
- Limits OpenAI sets: at least 25,000 matched users to target a list, files deleted "usually no later than 24 hours" after upload, no view of individual matches, and no custom audiences for campaigns aimed at the EEA or Switzerland.
- Still unclear: whether turning off ad personalization stops your account from being matched to an advertiser's list. OpenAI's pages don't say.
- Who sees ads: Free and Go users only, not accounts identified or predicted as under 18.
What did 404 Media report?
404 Media reported that anyone willing to set up an ad account can put ads into ChatGPT sessions using personal data, and that most of ChatGPT's users probably don't know it. Cox wrote that this kind of targeting is "somewhat standard" in online advertising, but that using people's prompts for it is new.
According to MobileSyrup's summary of the report, 404 Media ran two test ads arguing that ChatGPT isn't private. It used OpenAI's "context hints" to aim them at people asking about privacy and AI topics, without uploading anyone's personal data. Gadget Review reported that 404 Media quoted Zach Edwards of DecryptAds, who called OpenAI's approach "boiling the frog."
An OpenAI spokesperson told 404 Media that "being on an advertiser's list does not, by itself, cause an ad to be shown," per MobileSyrup. MobileSyrup also reported that OpenAI told 404 Media uploaded data is deleted after 24 hours and that people can only be "included" in targeting through lists of more than 25,000 users. OpenAI's own docs, below, put the floor at 25,000 matched users and say files are deleted "usually no later than 24 hours" after upload.
How are ChatGPT ads targeted by your prompts?
Your current conversation is the baseline, and you can't switch it off. OpenAI's "Ads in ChatGPT" help page says that even with ad personalization off, "you will still see ads based on the context of your current chat thread."
With personalization on, OpenAI can also use "past chats and memory" and "how you interact with ads," including ads you hide or click. On the advertiser side, "Ads in ChatGPT: The Basics" says ads are matched on "the context and intent of the current conversation," plus "select signals" from a user's wider ChatGPT use when personalization is on.
Advertisers don't buy keywords. They write context hints, descriptive phrases that OpenAI says "help guide ad matching" but "are not exact-match keywords." Our Ads Manager guide covers how campaigns are built.
Can advertisers target you by email or phone number?
Yes, as a group. OpenAI's Help Center article "Set up Custom Audiences for your Campaign" lists the identifiers an advertiser can upload in a CSV or TXT file:
| Identifier | Format OpenAI accepts |
|---|---|
| Raw, normalized to lowercase | |
| Phone number | Raw, in E.164 format with country code |
| Hashed email | SHA-256 of the lowercase, trimmed address |
| Hashed phone number | SHA-256 of the E.164 number |
| Google Advertising ID (GAID) | Raw, not hashed |
Last verified: October 18, 2026
Ads Manager then checks which rows match ChatGPT users, which OpenAI says usually takes 20 to 30 minutes. An advertiser can use a list in three ways:
- Include it: only matched people are eligible. This needs at least 25,000 matched users, and OpenAI recommends 100,000.
- Exclude it: matched people won't see the campaign. There's no minimum size.
- Bid more or less: multipliers from 0.1x to 10x for matched people. This also needs 25,000 matches.
Hashed values go through the same matching as raw ones, so hashing a list doesn't stop it from reaching the people on it.
What does OpenAI say protects users?
OpenAI's pages list these limits. They're company commitments, and no outside audit has checked them.
- No individual targeting in the tool: "Ads Manager does not show individual matched users or let you select specific people from an audience."
- Short retention: "Uploaded audience files are deleted after processing, usually no later than 24 hours after upload."
- Where the data comes from: OpenAI's developer docs tell advertisers to upload only "first-party audience data that you have the right to use for ads," and say "Don't upload broker-sourced data." OpenAI doesn't describe how it checks this.
- Not in Europe yet: custom audiences aren't supported for campaigns targeting the EEA or Switzerland, "where personalized ads are not yet available."
- What advertisers get back: OpenAI's user help page says advertisers "never receive your chats, chat history, memories, name, email, precise location, IP address." Its Privacy Center says OpenAI "does not sell your data or share your ChatGPT conversations with advertisers or marketing partners."
OpenAI's privacy policy, updated September 10, 2026, says it receives "information from advertisers and other data partners," including for ads shown to Free and Go users. Its example is "information about purchases you make from these advertisers." The policy doesn't mention customer lists or hashed contact details.
Does turning off ad personalization stop list targeting?
OpenAI hasn't said. The user help page describes what changes when personalization is off (past chats, memory and ad history stop being used), but it doesn't mention advertiser lists at all. The custom audiences pages don't say whether a user's personalization setting is checked before matching. The only setting-based limit they describe is the EEA and Switzerland exclusion.
Here's what you can control, per OpenAI's help page:
- Settings > Ad controls: turn off ad personalization, or only the past chats and memory signal.
- "About this ad" in an ad's three-dot menu, to see why you're being shown it.
- Delete ads data, which clears ad history and topics. OpenAI says it is "retained for up to 30 days" before being removed.
- Temporary Chat, which shows no ads.
- No ads at all: switch Free to the lower-limit Ads-Free mode, or pay for Plus or a higher plan. Our ads explainer has the steps, and our plans comparison has the prices.
Why it matters
Customer-list matching is routine on Google and Meta. ChatGPT is different because many people tell it things they wouldn't type into a search box. On OpenAI's description, a list can't trigger an ad by itself, and the conversation still has to fit. That means the ad you see can reflect both who an advertiser thinks you are and what you just asked. For how ads fit OpenAI's business, see OpenAI explained.
What's confirmed, reported and uncertain
- Confirmed (OpenAI docs, checked October 18, 2026):
- the five identifier types
- the 25,000-match minimum for inclusion and bid multipliers, and no minimum for exclusion
- the deletion of uploaded files, usually within 24 hours
- no individual-level view for advertisers
- no custom audiences for EEA or Switzerland campaigns
- current-chat targeting even with personalization off
- Reported (404 Media, October 15, via MobileSyrup and Gadget Review):
- 404 Media's test ads
- the OpenAI spokesperson's statement on lists
- Zach Edwards' comments
- Uncertain:
- whether ad personalization settings affect list matching
- how OpenAI checks that uploaded lists are first-party and lawfully collected
- when custom audiences first launched. Trade outlets give different dates, and OpenAI hasn't published one.
About this storyBased on the sources linked below. Editorial standards
