How to measure offline sales in Meta Ads (without losing your mind): The magic of the Offline Conversions API

Ever launched a Facebook or Instagram campaign, only to see your store flood with customers… but with no way to prove it was thanks to your ads? Welcome to the jungle of modern marketing.

But don’t worry—Meta’s got you covered with the Offline Conversions API. And here’s why this tool is key to understanding what happens beyond the click.

TABLE OF CONTENTS

• What is the Offline Conversions API?
• How does it work?
• Current status & future
• What now? Adsmurai One Tag

What is the Offline Conversions API?

Meta’s Offline Conversions API (formerly Facebook) lets advertisers send conversion events that happen outside the digital world—like in-store purchases, phone sales, and more—directly to Meta’s servers. In other words, it’s that friend who connects everyone at the party: syncing your digital efforts with real-world outcomes.

You can send offline conversion data (e.g., in-store purchases, phone calls, signed contracts) and match them to your Meta Ads campaigns. That way, you can finally know if that offline lead came from your retargeting ad—or just walked in by chance.

How does it work?

Meta doesn’t have cameras in your stores (yet 😅), but it can match the data you upload (name, email, conversion date, etc.) with users who interacted with your ads.

• Upload offline transaction data up to 62 days after the conversion to link sales to campaigns.
• Send info like timestamp, product details, and user data (email, phone, etc.) so Meta can identify if the person saw your ad.
• Perfect for businesses that take orders via phone, in-store, or through non-trackable channels.
• Enjoy a 28-day attribution window—longer than the standard 7-day pixel or CAPI tracking.

Bottom line: you can attribute offline conversions to your Paid Social campaigns.

What’s in it for me?

• Measure real ROI: No more crystal balls to figure out if your ads are working.
• Optimize campaigns: Feed Meta’s algorithm with these events and let the magic happen (well, almost).
• Better targeting: Build custom or lookalike audiences with this data. Offline buyers = prime lookalike seed.

Current status & future

Meta has announced the deprecation of the Offline Conversions API. Version 16.0 of the Graph API will be the last to support it, and the tool will be fully discontinued by May 2025. Meta recommends migrating to the Conversions API (CAPI), which now supports offline events too.

"We recommend that advertisers with existing Offline Conversions API integrations migrate to the Conversions API by May 2025..."

What now? Adsmurai’s got you

Since Meta put an expiration date on the Offline Conversions API, we at Adsmurai are already helping our clients transition to alternative solutions like:

• Custom integrations via CAPI for events that can be mapped as online conversions.
• CRM integrations that sync events in real time.
• Unified reporting to combine online and offline data in custom dashboards (hello, Looker Studio).

So yeah, the Offline Conversions API might be going away... but offline tracking is alive and kicking, and we know exactly how to keep it fresh and functional.

Adsmurai's solution: One Tag

Adsmurai has developed One Tag—a tool that allows you to implement the Facebook Conversions API directly via Google Tag Manager, no server setup or coding required. You just need:

• Your Facebook Pixel ID (from Events Manager)
• An Access Token (from the pixel settings in Facebook)
• Configure events in Google Tag Manager using the “Adsmurai Facebook Pixel & Conversions API (CAPI)” template and select One Tag as the server, inserting the API key provided by the platform

This solution is no-code, secure (data is hashed with SHA-256), and simplifies setup and maintenance—so you can focus on your business, not your infrastructure.

If your business depends on tracking offline conversions, it’s crucial to migrate to the new API before May 2025 to avoid losing tracking and attribution capabilities.