Competitor ad libraries: what they show and what they omit
They show who runs an ad, what it looks like and when, and in Europe add targeting and audience size. They list no spend or results for ordinary commercial ads, so use a library for ideas to test, not as evidence of what works.
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By Joris van Huët, Founder & CEOPublished 4 min read
The three official libraries show you what a competitor runs and when, not what it spends or sells. Meta's documentation lists spend and impressions for political and issue ads only. Google's Ads Transparency Center lists the advertiser, the payer and the ads served over a period, and TikTok's Commercial Content Library lists creative, dates, main targeting parameters and audience size, for Europe. None of the three pages lists conversions or revenue.
What does each library show on 30 September 2026?
The table is what each platform's own documentation says.
| Library | Covers | Shows | Spend and results |
|---|---|---|---|
| Meta Ad Library (API reference) | Ads on Meta technologies such as Facebook and Instagram, searched by country | Ad text, platforms, scheduled start and stop. Ads in the UK and EU add targeting and reach. Ads in the EU add payers and estimated EU reach | Spend and impressions for political and issue ads only. Results not listed |
| Google Ads Transparency Center | Search, Display, Gmail and YouTube | Advertiser name, location, payer, the ads served over a period. Some regions add targeting, recipients per ad and a subject label | Not listed |
| TikTok Commercial Content Library | Europe | Creative, dates the ad ran, main targeting parameters, people served. Kept until one year after the ad was last shown | Not listed |
The exact words: Meta's reference marks spend and impressions "Available only for POLITICAL_AND_ISSUE_ADS", and target ages, genders and locations "Available only for ads delivered to the UK & EU and POLITICAL_AND_ISSUE_ADS delivered to Brazil". Google's policy page calls the center "a searchable repository of advertisers and the ads they’ve served on Google platforms like Search, Display, Gmail, and YouTube". TikTok's newsroom post of 20 July 2023 lists "the advertising creative, dates the ad ran, main parameters used for targeting (e.g. age, gender), number of people who were served the ad, and more".
What do they leave out?
- Spend and results. Meta ties spend to political and issue ads, so an ordinary commercial ad has none. The Google and TikTok pages list no spend, clicks or conversions (TikTok's list ends "and more"). A spend or ROAS figure shown next to an ad in another tool is not one of these documented fields, so ask its vendor where it comes from.
- Delivery. Meta words its start field as "Date and time when an advertiser wants to start delivering an ad." Read "running since March" as "scheduled from March".
- Geography. TikTok's developer page says "in this phase we are ONLY including data from EU countries", so an ad shown only outside Europe is not there. Meta's API searches by country, and Google provides API access to "ads served in the EEA".
- Memory. TikTok keeps ad data "until one year since the advertisement was last shown to any user", so an ad last shown more than a year ago is gone.
Can a library tell you which ad works?
No. It tells you an ad existed. Reach says an ad was delivered, not that anyone bought, and a long-running ad may be a winner or an evergreen ad nobody switched off. The live Meta post walks through Meta's fields and the three ways a teardown misreads them. The same limits apply to the other two libraries.
How do you use a library without fooling yourself?
- Pick three competitors and search each in the libraries that cover your market.
- For each live ad, write down your own first-seen date, the format, the hook, the offer and the landing page. Your dates are yours; a library date may be the advertiser's schedule.
- Once a month, note which ads are new and which are gone.
- Choose one element to borrow and test it: change one thing, split the audience so the groups do not overlap, and judge it on your own revenue and margin, not only on the platform's attributed purchases. A Meta creative test is not an A/B test says why the split matters.
- The pass is a written hypothesis with a test and a stop date. The fail is "they scale this" with no number you can check.
Sources, 30 September 2026: Archived ad reference (Meta for Developers, 2026); Ads archive reference (Meta for Developers, 2026); Ads transparency (Google Advertising Policies Help, 2026); Expanding TikTok's Research API and Commercial Content Library (TikTok Newsroom, 20 July 2023); Commercial Content API (TikTok for Developers, 2026).
Related answers
Frequently asked questions
Can I see a competitor's ad spend in any of the three libraries?
Not for ordinary commercial ads, according to the documentation. Meta lists spend and impressions for political and issue ads only, and the Google and TikTok pages list no spend. A spend figure shown next to an ad in another tool is not one of these fields.Can I see a competitor's TikTok ads?
In TikTok's Commercial Content Library, for ads shown in Europe. TikTok's developer page says it covers EU countries in this phase and keeps ad data until one year since the ad was last shown, so an ad that ran only outside Europe is not in it.What does Google's Ads Transparency Center show?
A searchable repository of advertisers and the ads they have served on Search, Display, Gmail and YouTube, with the advertiser's name, location and payer. Some regions add targeting information and the total number of recipients per ad. Google's page lists no spend or results.
Go deeper: Causal attribution, explained.
Sixty-second versions of these ideas: Causality Engine on YouTube Shorts.
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Terms in this article
- ConversionConversion is a specific, desired action a user takes in response to a marketing message, such as a purchase or a sign-up.
- Google AdsGoogle Ads is an online advertising platform where advertisers bid to display ads, service offerings, and product listings.
- Holdout TestA holdout test is an experiment where a portion of the audience does not see a campaign. This measures the campaign's true incremental impact.
- ImpressionAn Impression counts each time an ad or content displays on a user's screen. It measures exposure, not engagement.
- IncrementalityIncrementality measures the true causal impact of a marketing campaign. It quantifies the additional conversions or revenue directly from that activity.
- Incrementality TestingIncrementality Testing measures the additional impact of a marketing campaign. It compares exposed and control groups to determine causal effect.
- Landing PageLanding Page: A single web page that appears after clicking a search result, marketing promotion, email, or online advertisement.
- RevenueRevenue is the total income generated by the sale of goods or services related to a company's primary operations.