The shared library is the part of a Google Ads account that stores settings you build once and apply to many campaigns, such as negative keyword lists, placement exclusion lists, shared budgets and portfolio bid strategies. Change an item there and every campaign using it picks up the change.
How the shared library works
You reach it from the Tools menu in Google Ads. The exact layout moves as Google redesigns the interface, but at the time of writing (October 2026) the shared library holds, among other things:
- Negative keyword lists: groups of terms you never want to show for, such as “jobs”, “free” or “DIY”, attached to as many campaigns as you like.
- Placement exclusion lists: websites, apps and YouTube channels where you do not want display or video ads to appear.
- Shared budgets: one daily amount drawn on by several campaigns.
- Bid strategies: portfolio strategies that pursue one target across a group of campaigns.
- The audience manager and the asset library, where audiences and images are stored for reuse.
Items in the library are linked, not copied. When a garden centre in Kent adds “wholesale” to its negative list, every campaign attached to that list stops showing for wholesale searches straight away. In a manager account, some lists can be built once and applied to several client accounts, which agencies and multi-brand businesses use to keep exclusions consistent.
Why it matters
Without the shared library, every campaign needs its own copy of every exclusion. Copies drift: someone adds a negative to one campaign, forgets the other four, and the account keeps paying for the same irrelevant clicks elsewhere. Central lists make an account easier to keep honest, and they make an audit faster, because the rules live in one place rather than scattered across dozens of ad groups.
The library also makes risky changes easier to make by accident. Because one edit reaches many campaigns at once, adding a broad negative such as “cheap” to a shared list can quietly stop ads in campaigns where cheap was a perfectly good word, for example a budget storage business.
Common mistakes
- Building shared lists and then never attaching them to new campaigns, so the newest campaigns have no exclusions at all.
- One enormous negative list applied everywhere, including terms that block good traffic for some campaigns.
- Vague list names such as “List 1” that tell the next person nothing about what the list is for.
- Adding negatives at campaign level and in a shared list at the same time, so nobody knows which rule is blocking a search.
- Leaving old placement exclusion lists in place long after the campaigns they protected were paused, then wondering why reach is low on a new video campaign.
How to act on it
Open the shared library and list what is there. For each item, check which campaigns use it and whether it still makes sense. Split negative keywords into themed lists, for example job seekers, competitors and free or DIY intent, and name them so the purpose is obvious. Use the search terms report every week to find new terms to add, and decide each time whether a term belongs in a shared list or only in one campaign.
When you launch a new campaign, add attaching the shared lists to your setup checklist. A tidy shared library is one of the quieter habits behind a well-run account, and it is a standard part of how I run monthly Google Ads management.