What is an ad library?

Ad libraries exist because of political pressure, not marketer demand. After the scrutiny that followed the 2016 US election, Meta launched a searchable archive of political ads in 2018 and extended it to all ads in 2019. Google followed with its Ads Transparency Center in 2023, and the EU’s Digital Services Act now obliges large platforms to maintain public ad repositories. TikTok and LinkedIn run their own.

What you get: the creative itself, the copy, run dates, placements, and the advertiser’s verified identity. What you mostly do not get: spend, reach, and targeting detail, which are disclosed only for political and issue ads in most regions, and performance data of any kind. The sharpest limitation is memory: a standard commercial ad disappears from the archive once it stops running, so the public record is a window, not a history.

For practitioners, the libraries are the primary source for competitor creative research, and because the native archives stop at search boxes, a market of ad library tools has grown on top of them. The market splits in two: swipe-file tools for creative teams who browse, save, and tag reference ads, and intelligence tools for structured, cross-platform data with stored history and API output, since Meta’s official API is scoped mainly to political ads and Google’s has none. Checking libraries by hand does not scale past a couple of brands, and because the history evaporates, whatever you did not capture is gone.

The Meta Ad Library

The largest archive: every ad running across Facebook and Instagram, searchable by advertiser or keyword, with years of retention for political ads and DSA-mandated detail in the EU. Full coverage, limits, and workflow on the Meta Ad Library page.

The Google Ads Transparency Center

Advertiser-first rather than ad-first: look up a verified advertiser and see its recent ads across Search, YouTube, and Display, within the recent window Google chooses to show. Detail on the Google Ads Transparency Center page.

The TikTok and LinkedIn ad libraries

Both born of the EU’s Digital Services Act and strongest in EU coverage, each with a specialty: TikTok’s Commercial Content Library carries unusually detailed targeting disclosure for EU ads, and the LinkedIn Ad Library is the record B2B teams read before pitches.

How do I search every ad library in one place?

Not through the native archives: each platform’s library only searches itself, and none stores history once a commercial ad stops running. Cross-library search means either checking each archive by hand, which does not scale past a couple of brands, or a tool that pulls all of them continuously and stores what it finds.

Is there an ad library API?

The platforms’ own APIs are narrow: Meta’s is scoped mainly to political and issue ads, and Google’s transparency surface has none. Third-party APIs fill the gap; Waldo’s discover_ads covers the Meta, Google, and LinkedIn libraries in one call, with TikTok through its own search endpoint, and every result keeps the native library’s own ID and deep link.

The major ad libraries, compared

1. Meta Ad Library: the biggest archive and the default starting point; keyword-searchable, but commercial ads vanish once they stop running.
2. Google Ads Transparency Center: best free view of a named advertiser’s Search and YouTube creative; advertiser-first, limited window, no keyword discovery.
3. TikTok Commercial Content Library: the most targeting detail of any archive, but reliably only for EU-targeted ads.
4. LinkedIn Ad Library: the B2B record; a year of retention, searchable by company, impression ranges on EU ads only.
5. Cross-platform layer (Waldo): one search and one API across the Meta, Google, and LinkedIn libraries plus TikTok, tracked daily and stored permanently, so the history the native archives forget is kept.

Native archives are free and authoritative for the platform they cover; the cross-platform layer exists because none of them searches the others or remembers what stopped running.

How this shows up in Waldo

Waldo scans the Meta and Google ad libraries daily for every tracked brand and stores what it finds permanently: creative, copy, and run dates survive after the ads leave the public archive, and every stored ad keeps the native library’s own id and deep link back to the source. One scan alone returned 5,184 Meta ads, and the same API reaches the LinkedIn and TikTok libraries on demand. The discover_ads MCP tool and its per-platform siblings run the same searches from inside Claude.

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