> For the complete documentation index, see [llms.txt](https://docs.mediarithmics.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.mediarithmics.io/connectors/destinations/browser-local-storage.md).

# Browser Local Storage

Write segment membership into the browser's local storage, where any on-site partner can read it.

The Browser Local Storage connector writes the segments a user belongs to into that user's **browser local storage**. No identifier leaves your CDP. A partner already running on your site reads the value and adapts the experience, or activates the user on-site.

<table data-search="false"><thead><tr><th width="220">Connection</th><th></th></tr></thead><tbody><tr><td><strong>Type</strong></td><td>Client-side (local storage)</td></tr><tr><td><strong>Category</strong></td><td><a href="/connectors/partner-types/on-site-personalisation.md">On-site personalisation</a></td></tr><tr><td><strong>Identifiers sent</strong></td><td>None - segment names only, kept in the browser</td></tr><tr><td><strong>Authentication</strong></td><td>None</td></tr></tbody></table>

## Description

### What this connector does

Rather than sending identifiers to a partner, the connector stores segment data in the visitor's local storage under a key you choose. Any partner integrated on your website can then read that key.

The value holds the **technical name** of each segment the user belongs to. If you did not set a technical name when creating the segment, mediarithmics assigns a default one, which you can change afterwards by editing the segment.

### What you can do with this connector

* Personalise on-site experience by segment, without sharing anything with a third party.
* Feed on-site partners that have no dedicated connector, through a custom process.
* Serve several partners from one feed, or give each its own key.

{% hint style="warning" %}
The Browser Local Storage connector can only be used for **on-site activation**. It does not send anything to a partner's servers.
{% endhint %}

### Which identifiers are sent

None. Nothing leaves the CDP; the segment list stays in the visitor's browser.

## Connector setup

### Prerequisites

* The mediarithmics tag installed on the site where the personalisation happens, calling `syncFeeds` - the call that enables client-side feeds. Without it, no segment is written to local storage. See the **Setup & Monitor** section, under *Collect & manage your data › Collect data in real time › Web tracking*.

### Setup steps

{% stepper %}
{% step %}
**Select the Browser Local Storage connector in the client-side section.**
{% endstep %}

{% step %}
**Fill in the configuration.**

<table data-search="false"><thead><tr><th width="260">Field</th><th></th></tr></thead><tbody><tr><td><strong>Name</strong></td><td>Identifies the feed in the platform. Any name; it is not visible on the site.</td></tr><tr><td><strong>Local Storage Field Name</strong></td><td>The local storage key that will hold the segments. Defaults to <code>mics_segments</code>. Connectors built on this one require a specific value - see below.</td></tr></tbody></table>
{% endstep %}
{% endstepper %}

Creating and activating the feed on a segment is covered in the **Audience & Activation** section, under *Activate your audiences › Send your first-party data to a destination*.

## Supported partners

Two partners have a dedicated page, because each expects a specific local storage key:

<table data-view="cards" data-search="false"><thead><tr><th></th><th></th><th data-hidden data-card-target data-type="content-ref"></th></tr></thead><tbody><tr><td><strong>AB Tasty</strong></td><td>Key must be <code>mediarithmics-segments</code>.</td><td><a href="/connectors/destinations/ab-tasty.md">AB Tasty</a></td></tr><tr><td><strong>Kameleoon - Client Side</strong></td><td>Key must be <code>mics_kam_seg</code>.</td><td><a href="/connectors/destinations/kameleoon/client-side.md">Client Side</a></td></tr></tbody></table>

The connector can also back custom processes with other partners - Google and FreeWheel, for example. Contact your account manager to work out how.

{% hint style="info" %}
[Curated Audiences (SDA)](/connectors/destinations/curated-audiences-sda.md) also writes to local storage, but to a fixed key (`mics_sda`) and in the IAB segment-taxonomy format. Use it when the consumer is a bidding integration such as Prebid.js rather than an on-site personalisation tool.
{% endhint %}

## Good to know

A newly activated segment does not appear in local storage straight away. For a segment ID to show up in the key, all of the following must have happened:

1. The user had a visit matching the rules of your segment.
2. The segment was **calculated after** that visit, so the user is genuinely in it.
3. The user came back to the website, **more than 24 hours after the first visit**.

The segment list is refreshed **once every 24 hours**, based on the `lastFeedRefreshDate` value stored in local storage.

## FAQ

#### Does any personal data leave my CDP?

No. The connector writes segment names into the visitor's own browser. Nothing is sent to a partner's servers.

#### Why is my segment not in the local storage key yet?

Most often because the segment has not been recalculated since the user's qualifying visit, or because the 24-hour refresh has not come round. See [Good to know](#good-to-know). If no segment ever appears, check that your tag calls `syncFeeds` - see [Prerequisites](#prerequisites).

#### What decides the segment name I see in the value?

The segment's **technical name**. If you did not set one, mediarithmics assigned a default, which you can change by editing the segment - see the **Audience & Activation** section, under *Build your audiences › Segment reference*.


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