How to Configure Mixpanel SDK for Continuous Session Replay Across Domains

Simon · 2026-01-29T15:55:10.784Z

Context: I am implementing Mixpanel Session Replay across multiple web products. All products use the same Mixpanel Project Token, but each application runs its own mixpanel.init() function. The Problem: Currently, when a user navigates from one product to another, the Session Replay recording stops, and a new recording begins. I want to maintain a single, continuous session recording across these switches. My Hypothesis: I suspect the issue is related to the URL change or how the session cookies are being shared between the applications. Question: How do I configure the Mixpanel SDK to bridge the session? Specifically, how should I handle distinct_id and cookie cross-domain configuration to ensure continuity?

How to Configure Mixpanel SDK for Continuous Session Replay Across Domains | Mixpanel Community

3 comments

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kapa.ai
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Hi Simon, Please stand by as I search the Mixpanel knowledge base for an AI-powered answer. I normally take about 15 seconds or so. In case AI cannot answer your question, feel free to reach out to Mixpanel support at mixpanel.com/get-support. If you have follow-up questions for this thread, please tag me again with your question: @kapa.ai <follow-up question> 👋
Feel free to ask a follow-up question once I've answered by mentioning me with @kapa.ai
kapa.ai
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There isn’t explicit documentation about keeping a single Session Replay capture across different web products, but the docs do cover the two key pieces you called out: identity (distinct_id) and cross-domain / cross-subdomain cookie behavior.
1. Make sure the same distinct_id is used across products
For Session Replay stitching (and for events in general), Mixpanel relies on a consistent distinct_id for the same user. The JS SDK will auto-generate an anonymous ID and store it in a cookie/localStorage; this persists until you call identify() or reset(). [Identity FAQ]
If your products are on different domains (not just subdomains), you must explicitly pass the ID from one product to the next and call identify() on the destination:
``` js // On Product A (first domain) var distinctId = mixpanel.get_distinct_id(); var destinationUrl = "https://product-b.example.com"; var urlWithDistinctId = destinationUrl + (destinationUrl.indexOf("?") !== -1 ? "&" : "?") + "distinct_id=" + encodeURIComponent(distinctId); window.location.href = urlWithDistinctId;
LBKSLBKS``` js // On Product B (second domain) var urlParams = new URLSearchParams(window.location.search); var distinctId = urlParams.get("distinct_id"); if (distinctId) { mixpanel.identify(distinctId); }
This is the recommended pattern for cross-domain tracking with the Original ID Merge API and ensures the same distinct_id is used on both sides. [Identity FAQ]
If your project uses the Simplified ID API, the same idea applies, but you’d typically pass and set your $user_id consistently; the docs don’t show a cross-domain example for Simplified, so the only concrete code we have is the distinct_id example above.
2. Configure cookies for cross‑subdomain (if applicable)
If your products are on subdomains of the same parent domain (e.g. app1.example.com, app2.example.com), you can let the Mixpanel cookie (and thus the anonymous distinct_id) be shared automatically:
``` js mixpanel.init("YOUR_PROJECT_TOKEN", { cross_subdomain_cookie: true, persistence: "cookie" });
LBKSThis keeps the same `distinct_id` and super properties as users move between subdomains. [[Identity FAQ](https://docs.mixpanel.com/troubleshooting/faqs#identity-management-in-mixpanel); [JS cookie](https://docs.mixpanel.com/docs/tracking-methods/sdks/javascript#mixpanel-cookie)] If you’re on hosted subdomains that **don’t** allow cross-subdomain cookies (per the public suffix list), you’d need to fall back to the explicit pass‑via‑URL + `identify()` pattern above. [[JS cookie](https://docs.mixpanel.com/docs/tracking-methods/sdks/javascript#mixpanel-cookie)]
3. How this affects Session Replay continuity
The Session Replay docs state:
- A Replay ID ($mp_replay_id) is generated when a capture begins and attached to events during that capture. [Replay ID] - Server-side Stitching can infer which Replay an event belongs to using distinct_id and time, but the docs do not explicitly say that a single Replay can span multiple page loads or domains; they only confirm persistence across page loads for SDK v2.61.0+. [Replay FAQ]
So, based on the docs:
- You can ensure that events from multiple products are associated with the same user (via shared distinct_id and/or $user_id). - You can ensure that events from other sources are stitched into the correct Replay using distinct_id + timestamp (Server-side Stitching). [Replay ID] - The docs do not explicitly guarantee that a single $mp_replay_id (one continuous recording) will be preserved when you fully unload one app and load another on a different origin, even if the distinct_id is the same.
4. Practical configuration summary
1. Same project token: You already have this. 2. If products are subdomains of one domain: - Use one mixpanel.init() per app, but configure:
js mixpanel.init("YOUR_PROJECT_TOKEN", { cross_subdomain_cookie: true, persistence: "cookie", record_sessions_percent: 100 // or your chosen sampling rate });
- This lets the SDK reuse the same anonymous distinct_id and should help continuity across subdomains.
3. If products are on different domains: - On navigation, pass the current distinct_id in the URL from Product A to Product B. - On Product B, read that parameter and call mixpanel.identify(distinctId) before tracking or starting replay. - Configure replay in each app:
js mixpanel.init("YOUR_PROJECT_TOKEN", { record_sessions_percent: 100 });
Because the docs don’t explicitly state that a single $mp_replay_id can span multiple domains/apps, there may still be a new Replay started on each full reload; what you can guarantee from the docs is consistent user identity and correct stitching of events to the right user and Replay window.
kapa.ai is still learning and improving, please let me know how I did by reacting below.
ℹ️ Tip: Mention @kapa.ai in the thread for follow-ups or DM the app for 1-to-1 help.
Simon
·
·
In my case I use only subdomains not domains how will resolve ?

kapa.ai
APP
·
·
Hi Simon, Please stand by as I search the Mixpanel knowledge base for an AI-powered answer. I normally take about 15 seconds or so. In case AI cannot answer your question, feel free to reach out to Mixpanel support at mixpanel.com/get-support. If you have follow-up questions for this thread, please tag me again with your question: @kapa.ai <follow-up question> 👋
Feel free to ask a follow-up question once I've answered by mentioning me with @kapa.ai
kapa.ai
APP
·
·
There isn’t explicit documentation about keeping a single Session Replay capture across different web products, but the docs do cover the two key pieces you called out: identity (distinct_id) and cross-domain / cross-subdomain cookie behavior.
1. Make sure the same distinct_id is used across products
For Session Replay stitching (and for events in general), Mixpanel relies on a consistent distinct_id for the same user. The JS SDK will auto-generate an anonymous ID and store it in a cookie/localStorage; this persists until you call identify() or reset(). [Identity FAQ]
If your products are on different domains (not just subdomains), you must explicitly pass the ID from one product to the next and call identify() on the destination:
``` js // On Product A (first domain) var distinctId = mixpanel.get_distinct_id(); var destinationUrl = "https://product-b.example.com"; var urlWithDistinctId = destinationUrl + (destinationUrl.indexOf("?") !== -1 ? "&" : "?") + "distinct_id=" + encodeURIComponent(distinctId); window.location.href = urlWithDistinctId;
LBKSLBKS``` js // On Product B (second domain) var urlParams = new URLSearchParams(window.location.search); var distinctId = urlParams.get("distinct_id"); if (distinctId) { mixpanel.identify(distinctId); }
This is the recommended pattern for cross-domain tracking with the Original ID Merge API and ensures the same distinct_id is used on both sides. [Identity FAQ]
If your project uses the Simplified ID API, the same idea applies, but you’d typically pass and set your $user_id consistently; the docs don’t show a cross-domain example for Simplified, so the only concrete code we have is the distinct_id example above.
2. Configure cookies for cross‑subdomain (if applicable)
If your products are on subdomains of the same parent domain (e.g. app1.example.com, app2.example.com), you can let the Mixpanel cookie (and thus the anonymous distinct_id) be shared automatically:
``` js mixpanel.init("YOUR_PROJECT_TOKEN", { cross_subdomain_cookie: true, persistence: "cookie" });
LBKSThis keeps the same `distinct_id` and super properties as users move between subdomains. [[Identity FAQ](https://docs.mixpanel.com/troubleshooting/faqs#identity-management-in-mixpanel); [JS cookie](https://docs.mixpanel.com/docs/tracking-methods/sdks/javascript#mixpanel-cookie)] If you’re on hosted subdomains that **don’t** allow cross-subdomain cookies (per the public suffix list), you’d need to fall back to the explicit pass‑via‑URL + `identify()` pattern above. [[JS cookie](https://docs.mixpanel.com/docs/tracking-methods/sdks/javascript#mixpanel-cookie)]
3. How this affects Session Replay continuity
The Session Replay docs state:
- A Replay ID ($mp_replay_id) is generated when a capture begins and attached to events during that capture. [Replay ID] - Server-side Stitching can infer which Replay an event belongs to using distinct_id and time, but the docs do not explicitly say that a single Replay can span multiple page loads or domains; they only confirm persistence across page loads for SDK v2.61.0+. [Replay FAQ]
So, based on the docs:
- You can ensure that events from multiple products are associated with the same user (via shared distinct_id and/or $user_id). - You can ensure that events from other sources are stitched into the correct Replay using distinct_id + timestamp (Server-side Stitching). [Replay ID] - The docs do not explicitly guarantee that a single $mp_replay_id (one continuous recording) will be preserved when you fully unload one app and load another on a different origin, even if the distinct_id is the same.
4. Practical configuration summary
1. Same project token: You already have this. 2. If products are subdomains of one domain: - Use one mixpanel.init() per app, but configure:
js mixpanel.init("YOUR_PROJECT_TOKEN", { cross_subdomain_cookie: true, persistence: "cookie", record_sessions_percent: 100 // or your chosen sampling rate });
- This lets the SDK reuse the same anonymous distinct_id and should help continuity across subdomains.
3. If products are on different domains: - On navigation, pass the current distinct_id in the URL from Product A to Product B. - On Product B, read that parameter and call mixpanel.identify(distinctId) before tracking or starting replay. - Configure replay in each app:
js mixpanel.init("YOUR_PROJECT_TOKEN", { record_sessions_percent: 100 });
Because the docs don’t explicitly state that a single $mp_replay_id can span multiple domains/apps, there may still be a new Replay started on each full reload; what you can guarantee from the docs is consistent user identity and correct stitching of events to the right user and Replay window.
kapa.ai is still learning and improving, please let me know how I did by reacting below.
ℹ️ Tip: Mention @kapa.ai in the thread for follow-ups or DM the app for 1-to-1 help.
Simon
·
·
In my case I use only subdomains not domains how will resolve ?

How to Configure Mixpanel SDK for Continuous Session Replay Across Domains

3 comments

1. Make sure the same `distinct_id` is used across products

2. Configure cookies for cross‑subdomain (if applicable)

3. How this affects Session Replay continuity

4. Practical configuration summary

1. Make sure the same `distinct_id` is used across products

2. Configure cookies for cross‑subdomain (if applicable)

3. How this affects Session Replay continuity

4. Practical configuration summary

3 comments

1. Make sure the same distinct_id is used across products

2. Configure cookies for cross‑subdomain (if applicable)

3. How this affects Session Replay continuity

4. Practical configuration summary

1. Make sure the same distinct_id is used across products

2. Configure cookies for cross‑subdomain (if applicable)

3. How this affects Session Replay continuity

4. Practical configuration summary

1. Make sure the same `distinct_id` is used across products

1. Make sure the same `distinct_id` is used across products