LinkedIn Conversions API: how to set up server-side conversion tracking on LinkedIn.

What LinkedIn Conversions API is

LinkedIn Conversions API (CAPI) is LinkedIn's server-to-server endpoint for conversion events, particularly valuable for B2B advertisers running long sales cycles. LinkedIn launched CAPI in beta in 2022 and made it generally available in 2023. The use case differs from Meta and TikTok: LinkedIn CAPI primarily supports offline conversion tracking (lead to opportunity, opportunity to deal) rather than browser-event recovery.

Why LinkedIn advertisers need CAPI

B2B sales cycles often run 30-180 days. The original lead conversion fires in the browser; the meaningful conversion (qualified opportunity, closed deal) happens in the CRM weeks or months later. LinkedIn CAPI bridges the gap by accepting offline conversion uploads, letting LinkedIn's bidding optimize for deal-stage outcomes rather than just MQL volume.

Setup walkthrough

1. Create a CAPI integration in Campaign Manager.Account Assets > Conversions API integrations > Create new. Generate the auth credentials.
2. Map your CRM stages to LinkedIn conversion events.MQL > Conversion. SQL > Lead. Closed deal > Sale. Each stage maps to a LinkedIn conversion action.
3. Build the CRM-to-LinkedIn integration.Most teams use Zapier, Workato, or a custom integration. The integration listens for CRM stage changes and POSTs the conversion to LinkedIn CAPI.
4. Include LinkedIn UUID or hashed email.LinkedIn matches conversions to ad clicks via LinkedIn user UUID (from li_fat_id cookie) or hashed email. Without one of these, the conversion cannot be attributed back.
5. Validate in Campaign Manager.Conversions tab shows received events and match status.

Payload format

LinkedIn CAPI accepts conversion events with: conversion (the conversion action ID), conversionHappenedAt (Unix timestamp), conversionValue (revenue and currency), and user (LinkedIn UUID or hashed email/phone). The minimal viable payload is the conversion action plus the user identifier.

Deduplication

LinkedIn deduplicates by conversion_id within 90 days. If you upload the same conversion twice, LinkedIn keeps the first one. For ongoing CRM-stage updates (lead becomes opportunity becomes deal), use distinct conversion actions for each stage rather than updating the same conversion record.

Common implementation mistakes

Three failures. Trying to use LinkedIn CAPI for browser-event recovery (it is built for offline conversions; Meta CAPI is for browser events). Missing the LinkedIn UUID and only sending hashed email, which produces lower match rates. Not mapping each CRM stage to a separate LinkedIn conversion action.

Quick answers

What is LinkedIn Conversions API?

LinkedIn's server-to-server endpoint for conversion events. Mainly for offline B2B conversions (qualified leads, closed deals).

How is it different from Meta CAPI?

Meta CAPI is for browser-event recovery. LinkedIn CAPI is for offline conversion uploads from your CRM. Different problem, different use case.

Do I need it for top-of-funnel?

Less than for bottom-of-funnel. The biggest LinkedIn CAPI value is uploading qualified-lead and closed-deal conversions back to LinkedIn so the bidder optimizes for revenue-stage outcomes.

What identifier does LinkedIn need?

LinkedIn user UUID (from li_fat_id cookie) is the primary matcher. Hashed email is the fallback. Always send both if you can.

How long does it take to implement?

3-8 weeks. Most of the time is on the CRM-to-LinkedIn integration, not the LinkedIn API itself.

Should I use Zapier or build custom?

Zapier for sub-100-leads-per-month accounts. Workato or custom for higher volumes. The integration logic is mostly mapping CRM events to LinkedIn conversion actions.

Frequently asked

What is LinkedIn Conversions API?

LinkedIn's server-to-server endpoint for conversion events, launched in beta in 2022 and generally available in 2023. Primary use case is offline B2B conversion tracking — uploading MQL, SQL, opportunity, and closed-deal conversions from your CRM back to LinkedIn for bidding optimization.

How is LinkedIn CAPI different from Meta CAPI?

Different use cases. Meta CAPI is built for browser-event recovery (replacing degraded Pixel data). LinkedIn CAPI is built for offline conversion uploads (replacing manual CSV uploads from CRM). Both solve attribution gaps but in different ways.

When should I use LinkedIn CAPI?

When you run paid LinkedIn campaigns with bidding optimized for conversion-stage outcomes (Lead Form, Conversions objectives). The CAPI uploads let LinkedIn's bidder optimize against your actual revenue stages rather than just top-of-funnel MQL volume.

What is the LinkedIn UUID?

LinkedIn's user identifier captured in the li_fat_id cookie when a user clicks an ad. Pass it through your CRM to LinkedIn CAPI when uploading conversions for exact-match attribution.

Can I use email matching only?

Yes but match rates are lower. LinkedIn matches hashed email to user profiles but the match rate is materially worse than LinkedIn UUID. Always capture and pass UUID when possible.

How do I integrate LinkedIn CAPI with my CRM?

Three options. Native integrations (LinkedIn provides Salesforce, HubSpot, and Microsoft Dynamics connectors). Zapier or Workato for lower-volume accounts. Custom integration via the LinkedIn API for high-volume needs.

What is the typical implementation timeline?

3-8 weeks. Most of the time is on the CRM-to-LinkedIn integration logic. The LinkedIn API itself is straightforward.

Does LinkedIn CAPI support attribution beyond first conversion?

Yes. Each CRM stage (MQL, SQL, opportunity, deal) can be mapped to its own LinkedIn conversion action. LinkedIn's bidder can then optimize for deal-stage outcomes rather than just MQL volume.