> For the complete documentation index, see [llms.txt](https://doc.commandersact.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://doc.commandersact.com/features/identity-resolution/migrate-from-fuse-v1-to-fuse-v2.md).

# Migrate from Fuse v1 to Fuse v2

## What are the differences between V1 and V2?

On **Fuse V1,** the goal was to **identify** same users and **duplicate** for each visitor (cookie based) all the user data you could have on this person.\
For example, you collected data about a visitor A with a laptop and a visitor B with a mobile phone. If the Fuse algorithm noticed that visitor A = visitor B, it duplicates the information from visitor B to visitor A and vice-versa. So you can have an overview of visitors who shared the same information and are linked.

![](https://1259070148-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Mk6XpTQ2LaRLcr2tA-d%2Fuploads%2Fgit-blob-108ef6f281fc939afaab033c81752b2544c7c6ce%2Fimage.png?alt=media)

With **Fuse V2,** it goes further by **merging** these visitors in order to have a **unique user** with all the data collected. With Fuse V2, the goal is to detect with multiple reconciliation keys the same customer and unify all the data around 1 unique user in order to have a complete view of the customer across all devices and all channels.

![](https://1259070148-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-Mk6XpTQ2LaRLcr2tA-d%2Fuploads%2Fgit-blob-eb3f4d2db60933feb56ac4755c4e4f91de1dafd4%2Fimage.png?alt=media)

With Fuse V2 your CDP become **user-centric** rather than cookie centric and that change the way you define your marketing campaigns: you don’t talk to devices anymore but to persons directly, to users.

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