What Is LinkedIn's Conversions API Tool?

LinkedIn Conversions API (CAPI) is a server-side endpoint that lets your website or back-end system send conversion events directly to LinkedIn without relying on the browser. Because calls come from your server, data is less affected by ad-blockers, ITP, and cookie limits. The API connects your database to Campaign Manager, helping ensure more qualified leads or sales are counted by reducing browser-side data loss.

Why LinkedIn Conversions API Matters

• Tie phone orders, CRM stages, or in-store sales to your campaigns for a complete view.
• Richer signals help LinkedIn lower CPA automatically. Advertisers using CAPI report +31% attributed conversions, −20% CPA, and −39% cost per qualified lead on average.
• Server calls survive browser restrictions that can drop the LinkedIn Insight Tag.
• Choose exactly which hashed fields are shared (SHA256_EMAIL, first-party tracking UUID, or third-party identity IDs like ACXIOM_ID and ORACLE_MOAT_ID).
• Server-side SHA-256 hashing, 180-day data retention, and member ad-preference controls simplify compliance with GDPR, CCPA, and similar privacy laws.
• Near real-time updates reach Campaign Manager sooner, letting bid strategies adapt before budget is wasted.

SaaS teams use CAPI to stream SQL events. E-commerce shops push net revenue. B2B marketers sync webinar and trade-show data. For sales funnel automation and campaign optimization on LinkedIn, see the LinkedIn Automated Marketing Funnel: Sales Funnel Automation Guide.

How LinkedIn Conversions API Works

Client-side vs. server-side:

• Pixel: browser collects click/view data; susceptible to blockers.
• API: your server POSTs JSON to LinkedIn's /rest/conversionEvents endpoint using an OAuth2 access token (with rw_conversions and r_ads scopes) and four required headers: Authorization: Bearer {token}, X-Restli-Protocol-Version: 2.0.0, LinkedIn-Version: {yyyymm}, and Content-Type: application/json.

Conversion events must have a conversionHappenedAt timestamp within the past 90 days. Attribution lookback windows can be configured to 1, 7, 30, or 90 days; 365-day windows are available for Lead, Qualified Lead, Purchase, Submit Application, and Add to Cart conversion types.

Step-by-Step Setup

1. Create a conversion rule — in Campaign Manager go to Measurement → Conversion tracking → Create conversion → Conversions API. Name the rule, pick a conversion type (Lead, Purchase, Sign Up, etc.), set a value method (dynamic, fixed, or none), and configure attribution windows.
2. Choose an integration path — either connect through a partner (Adobe, HubSpot, Google Tag Manager, Zapier, Segment, Tealium, and others) or build a direct integration against LinkedIn's REST API. Partner setups are typically one-time; direct integrations take 2–4 weeks on average and give full control over the payload.
3. Generate an OAuth2 access token — your app needs the rw_conversions and r_ads scopes. The token owner must hold an Account Manager, Campaign Manager, or Billing Admin role on the ad account.
4. Associate campaigns — attach the conversion rule to every campaign that should receive credit. Use autoAssociationType=ALL_CAMPAIGNS when creating the rule, or associate manually via PUT /rest/campaignConversions.
5. Stream events — POST each conversion to /rest/conversionEvents with the conversion URN, a millisecond timestamp, at least one user identifier, and an optional eventId for deduplication.

User Matching Keys

LinkedIn resolves events to members using identifiers you send in the userIds array:

• SHA256_EMAIL — lowercase, trimmed, SHA-256 hashed email.
• LINKEDIN_FIRST_PARTY_ADS_TRACKING_UUID — the li_fat_id click parameter captured when enhanced conversion tracking is enabled.
• ACXIOM_ID — LiveRamp identity graph.
• ORACLE_MOAT_ID — Oracle MOAT identity graph.
• If none of the above are available, send firstName + lastName (and optionally companyName, title, countryCode) in the userInfo object.

Sending multiple identifiers per event increases match rates. Only matched events count toward attribution and optimization.

Supported Conversion Types

LinkedIn accepts over 30 conversion types including Add to Cart, Download, Install, Key Page View, Lead, Purchase, Sign Up, Start Checkout, Subscribe, Qualified Lead, Submit Application, Phone Call, Book Appointment, Request Quote, and others. The full list is documented in the Marketing API reference.

Deduplication

If you run both the Insight Tag and CAPI, LinkedIn can deduplicate automatically. Pass the same eventId string with both the client-side and server-side event so LinkedIn recognizes the duplicate and counts it once.

Rate Limits

• 600 requests per minute per token.
• 300,000 requests per day per token.
• Batch endpoint accepts up to 5,000 events in a single POST (use the X-RestLi-Method: BATCH_CREATE header).

Best Practices

• Send events in real time. Delayed data can fall outside the attribution window or miss the optimization cycle.
• Include as many matching parameters as possible. More identifiers mean higher match rates and better signal quality.
• Enable enhanced first-party tracking in Campaign Manager so LinkedIn appends li_fat_id to landing-page URLs. Capture and forward this UUID with every conversion event.
• Set wide attribution windows. LinkedIn recommends 90-day click / 90-day view for lead and lower-funnel conversions. For long B2B sales cycles, use the 365-day window on Lead, Qualified Lead, Purchase, Submit Application, and Add to Cart types.
• Assign conversion values. Even static placeholder values let Campaign Manager calculate ROAS and surface high-value audiences.
• Associate conversions with all relevant campaigns. Unlinked campaigns cannot receive attribution credit.
• Use batch requests for bulk loads. Migrating historical CRM data or syncing nightly exports is faster and more reliable in batches of up to 5,000 events.
• Monitor the Conversion Tracking page in Campaign Manager for status alerts and verify events are arriving and matching.

Bonus Tips

• Pair CAPI with the Insight Tag rather than replacing it. Redundant signals fill gaps when one channel drops events, and LinkedIn deduplicates automatically.
• Use Google Tag Manager's server-side container to forward web events to CAPI without writing custom code—LinkedIn provides an official GTM template.
• Share proven conversion rules across ad accounts via Business Manager so every team uses the same measurement framework.
• Hash emails on your server before they leave your network. Pre-hashing keeps raw PII out of logs and transit.
• Refresh your OAuth token before it expires. A lapsed token silently drops events until someone notices the gap in Campaign Manager.
• Test your payload with LinkedIn's Payload Builder tool at linkedin.com/developers/payload-builder before going live.