Meta, TikTok, LinkedIn and Google ad libraries: how to spy on competitors (legally)

Why these libraries exist

Not out of generosity. Meta opened its library after Cambridge Analytica, to show who pays for what around elections. Then the EU Digital Services Act forced every large platform to publish a register of the ads it serves in the Union.

The practical upshot: these tools are built for transparency, not marketing. They are a bit bare, sometimes slow, and the useful filters are often tucked away. But everything is there.

The five tools side by side

Before the details, here is what each one gives you.

Meta Ad Library: the richest, especially in Europe

Go to facebook.com/ads/library. Pick a country, the “All ads” category, and type a brand or Page name. You see every active ad across Facebook, Instagram, Messenger and Audience Network, with launch date, placements and how many versions are running.

The European bonus: for ads served in the EU, Meta also shows estimated reach, a breakdown by age, gender and country, and the main targeting criteria. Every library has to do this for the EU under the DSA, but Meta presents it most clearly. Even if you sell in the US, try selecting an EU country where the brand is active: you will get more detail.

A trick few people use: the “Platform” and “Media type” filters. Keep only Instagram videos and you instantly see which Reels a brand chose to put money behind, which usually means the ones that did best organically.

Google Ads Transparency Center: Search, YouTube and the rest

Go to adstransparency.google.com. It covers Search, Display, YouTube, Shopping, Maps and Google Play. Search an advertiser by name or domain, then filter by country, format and date range.

What you actually learn: the copy of Search ads (headlines and descriptions), YouTube video ads and Display banners. What you don’t learn: which keywords trigger them. To guess, cross-check with your own Google searches in a private window, or with an SEO tool.

TikTok: two tools for two different jobs

The Creative Center (ads.tiktok.com/business/creativecenter) is for inspiration. It surfaces top-performing ads by industry and country, with relative metrics (CTR, completion rate) and current trends: sounds, hashtags, creators. It is the only place, across all platforms, where you see something resembling performance. But it is a selection made by TikTok, not a full register.

The Commercial Content Library (library.tiktok.com) is the official register required by the DSA. It only covers the EEA, Switzerland and the UK. For each ad: the advertiser, first and last date shown, and a range of how many people saw it. An ad can take up to 24 hours to appear.

LinkedIn Ad Library: made for B2B

Go to linkedin.com/ad-library. Search a company or keyword and see the ads it has run. For B2B it is a goldmine: which white papers your competitors push, how they frame their offer, whether they use Thought Leader Ads (sponsored posts from executives) or document ads.

For LinkedIn costs, see our LinkedIn Ads 2026 benchmarks.

What no library will tell you

No spend, no click-through rate, no conversions. An ad in the library can be a $5-a-day test that gets killed tomorrow. That is where most people go wrong: they copy the newest ad, which is exactly the one nobody knows works yet.

The reliable clues are elsewhere:

• Run time. Nobody keeps a money-losing ad live for three months. Sort by start date and look at the oldest ads still running.
• Number of versions. When Meta says “12 ads use this creative”, the brand rolled the visual out across several ad sets. They believe in it.
• Comebacks. A creative paused and relaunched a few weeks later is almost always a winner.
• EU reach. On Meta, reach in the hundreds of thousands on a commercial ad tells you there is budget behind it.

The 20-minute routine

Once a month is plenty. Pick three direct competitors and one brand you admire outside your industry.

And your own ads?

Remember your competitors can do exactly the same to you. That is no reason to stop testing, but it is a reason not to keep your best offers on permanent promotion: they become public.

To track your Meta, Google, TikTok and LinkedIn campaigns in one place, with real spend and real results (which no library gives you), Perroly brings everything together in its Ads module. And to check whether your costs are normal, compare them with our 2026 benchmarks.