# What is an ad library?

> An ad library is a searchable database of ads, run by a platform or a tool. What the free ones show, what they hide and how teams use them for research.
- **Author**: Marxx
- **Published**: 2026-11-06
- **Category**: Platforms
- **URL**: https://marxx.ai/library-glossary/ad-library

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An ad library is a searchable database of ads. Platforms keep public ones, such as the Meta Ad Library and the Google Ads Transparency Center. Ad research tools keep private ones, with extra data like saved boards and history.

## The main public libraries

| Library | Run by | What it is for |
|---|---|---|
| [Meta Ad Library](/glossary/meta-ad-library) | Meta | Active ads across Meta's apps, such as Facebook and Instagram |
| [Google Ads Transparency Center](/guides/how-to-use-google-ads-transparency-center) | Google | Ads run on Google Search, YouTube and other Google platforms |
| [TikTok Creative Center](/guides/how-to-use-tiktok-creative-center) | TikTok | Top ads and trends by country and industry |
| [LinkedIn Ad Library](/guides/how-to-see-competitor-ads-on-linkedin) | LinkedIn | Ads companies have run on LinkedIn |

All are free. Most show the ad itself and when it ran. Most do not show spend or results.

## What a library cannot tell you

An ad that has run for months is a clue, not proof. It may be profitable, or a brand may be slow to switch it off. Treat libraries as a source of ideas to test, not a scoreboard.

## A worked example

Say you check three rivals in the Meta Ad Library, and count ads that started in the last 14 days.

| Rival | Active ads | Started in last 14 days | Share new |
|---|---|---|---|
| A | 31 | 4 | 13% |
| B | 12 | 0 | 0% |
| C | 48 | 19 | 40% |

Rival C is testing the most. Open its 19 new ads and note the angles and hooks. Rival B is quiet, so there is little to learn there this month. Save what you find in a swipe file, so it is still there when the rival's ad is gone.

## Public library or research tool?

A public library is free and current, but it gives you no memory. When a rival ends an ad, it disappears from the Meta Ad Library, except ads that ran in the EU or UK in the past year and ads about social issues, elections or politics, which stay for seven years (Meta, checked 2026-10-20). A research tool keeps history, tags ads and lets you search across brands. Our list of [free ad spy tools](/best/best-free-ad-spy-tools) compares the options.

Marxx tracks competitor ads on Meta and Google, and has an AI search over 100M+ ads back to 2022. See [competitor tracking](/features/competitor-tracking).

## FAQ

### Is an ad library the same as a swipe file?

No. A library is a public or tool database of ads. A swipe file is your own saved collection of ads worth learning from.

### Do ad libraries show how much an ad spent?

Mostly not. Spend and results are hidden for most ads. A few categories, such as political ads, show more.

### Which ad library should I start with?

Start with the library for the platform you buy on. If you buy on Meta, that is the Meta Ad Library.

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