How Facebook Generates Event Match Quality Scores

You're spending thousands on ads, yet conversions seem to appear out of thin air or vanish when you try to match them to campaigns. That gut-drop feeling is common, and it has a name on Meta. It shows up as a low Event Match Quality score, and it is the reason your reports feel off and your optimization stalls.

Think of the Event Match Quality score as Facebook's report card for the customer data attached to your events. When the score is high, Meta can recognize who converted and connect the dots back to an ad view or click. When the score is low, the system is guessing, which means optimization slows, attribution breaks, and your ROAS suffers. A weak score is like running a marathon with one shoe.

Here is the good news. Once you grasp how Facebook calculates the Event Match Quality score and which data points matter most, you can raise it fast. Many teams see a 20 to 40 percent jump in conversion accuracy after boosting their score. Server-side tracking through the Facebook Conversions API is the foundation, and tools built for no-code platforms make it simple.

By the end of this guide, you will know how the score works, which identifiers move the needle, and practical steps to improve it on Webflow, Framer, Squarespace, and more. You'll also see how PixelFlow helps non-technical teams reach 8.3 to 9.3 out of 10 in minutes, not months.

What Is the Event Match Quality Score and Why Does It Matter?

The Event Match Quality score is Facebook's metric for how well your customer data matches real user profiles. It only applies to website events sent through the Conversions API with action_source set to website. The score runs from 0 to 10 and updates based on activity from the last 48 hours.

Here is how the ranges map:

• Poor covers 0 to 2.9 when matching is weak

• OK sits between 3 and 5.9 when signals are thin

• Good lives between 6 and 7.9 when data is decent

• Great is 8 to 10 when Meta can confidently link events to people

The higher your Event Match Quality score, the smarter your optimization and the cleaner your reporting.

"Better data quality means better ad performance. When Facebook can accurately match your conversions to real people, your campaigns learn faster and spend smarter." — Digital Marketing Institute

Think of EMQ like phone signal strength. Two bars drops calls. Ten bars gives you a crisp call and quick data. Low EMQ leads to lost conversions and slow learning. High EMQ feeds Meta strong fuel, so your ads find the right people faster and your CPA falls.

Privacy also fits into this picture. You send data in a privacy-safe way by hashing sensitive fields like email with SHA-256 before transmission. Facebook can still match, yet personal info is protected. In 2025, with cookie limits and link tracking protection, a solid Event Match Quality score is not a nice-to-have, it is how you keep ads profitable.

How Does EMQ Score Affect Your Ad Profitability?

When your score sits below 6, you are essentially flying blind. Meta cannot confidently tie purchases back to specific ads, which means:

• Your campaign optimization slows to a crawl

• Attribution windows shorten or break completely

• You miss out on Lookalike Audiences built from accurate conversion data

• Budget flows to the wrong ad sets

Many advertisers blame rising CPMs or increased competition when the real culprit is poor data matching. Fix your EMQ score first, and you will often see costs drop without changing your creative or targeting.

How Does Facebook Calculate Your Event Match Quality Score?

Facebook rates your score using a rolling 48-hour window. The system looks at the customer data attached to your web events and how often those events match a user account. Knowing these inputs gives you a direct path to improve the score and your results.

The Two Core Factors Facebook Evaluates

First comes the quality of customer information you send with each server event. Not all parameters carry the same weight. High-priority identifiers like hashed email and click ID carry much more value than city or zip code. Stacking strong signals on a single event boosts matching at a steep rate, which pushes the Event Match Quality score higher.

Second comes the match rate percentage. This is the share of your event instances that Meta ties to a user profile. The score blends deterministic matches, where an identifier like email hits an exact account, and probabilistic matches, where Meta uses IP, browser ID, and user agent to infer a link. The system calculates both factors across the last 48 hours, so consistent event sending keeps the score accurate.

Here is a simple picture. If you send 100 events with only IP, you might see a 20 percent match rate and an Event Match Quality score near 3 out of 10. Send the same 100 with hashed email, phone, fbc, and fbp, and match rate can climb above 80 percent with a score near 9 out of 10. Both strong data and strong match rate are required to reach the top tier.

Deterministic vs Probabilistic Matching Explained

Deterministic matching happens when the data you send lines up exactly with a user's account. A hashed email in your event that equals the hashed email on a profile is the cleanest link. The same applies to hashed phone or an external ID that you maintain across sessions. These matches carry very high confidence and drive faster optimization.

Probabilistic matching blends several technical signals to infer identity when direct identifiers are missing. IP combined with fbp, user agent, and session details can still create a useful link. While this method has lower confidence than a perfect email match, it still helps reporting and delivery, especially for anonymous visitors who never typed an email on your site.

Many sites see a mix of both visitor types. You may have logged-in buyers and anonymous browsers on the same day. This does not mean probabilistic data is worthless. Adding fbc and fbp gives Meta context that raises your Event Match Quality score even when email is absent.

What Customer Information Parameters Drive High EMQ Scores?

Here is the golden rule: More high-quality parameters on each event leads to much better matching. Facebook ranks identifiers by priority, so stack the best ones first and let the lower ones support them.

High Priority Parameters

High priority parameters start with email and click ID. A hashed lowercase email is the single most powerful identifier, since people keep the same email for years and use it to log in across devices. The fbc value, captured from the _fbc cookie, ties a session to an ad click, which closes the loop for attribution. These two alone can move an Event Match Quality score from the 3 range to the 7 range when added consistently.

Key high-priority identifiers include:

• Email address (hashed with SHA-256)

• fbc (Facebook Click ID from _fbc cookie)

• Client IP address

• Client user agent

Medium Priority Parameters

Medium priority parameters layer on phone number, external ID, and browser ID. A hashed phone with country code often maps to an account. An external_id from your CRM or eCommerce system is your secret weapon, since it follows the user across sessions and devices in a privacy-safe way. The fbp value from the _fbp cookie is vital for anonymous visitors, since it gives Meta a steady browser identifier. Combine email, phone, external_id, and fbp, and your score often reaches the 8.5 range or better.

Additional medium-priority parameters:

• Phone number (hashed, with country code)

• fbp (Facebook Browser ID from _fbp cookie)

• External ID (your internal customer identifier)

• Login ID (if users authenticate on your site)

Low Priority Parameters

Low priority parameters add extra context. First name, last name, city, zip code, date of birth, and country can help refine matches when top-tier data is missing. These do not replace email or phone, yet they tilt probabilistic matches in your favor and round out the picture.

Supporting identifiers include:

• First name and last name

• City and state

• Zip code or postal code

• Country code

• Date of birth

• Gender

Technical Implementation Notes

A few technical notes make a big difference:

• Hash all PII with SHA-256 before sending

• Normalize strings to lowercase and remove extra spaces and symbols

• Collect consent as required by GDPR and CCPA before sharing data

• Include country codes with phone numbers (+1 for US, +44 for UK, etc.)

• Use consistent formatting across all events

PixelFlow automatically hashes and formats parameters, which removes common mistakes that drag down your Event Match Quality score.

Common Reasons Your EMQ Score Is Lower Than It Should Be

If your Event Match Quality score sits below 6, you are dealing with one or more common issues. Use this quick diagnostic to spot the weak link and fix it fast.

Issue 1: Pixel-Only Tracking

Browser tracking keeps losing ground each month. Ad blockers stop a large share of pixel fires. Safari ITP and Firefox ETP shorten cookies or block them entirely. iOS 17 Link Tracking Protection strips fbclid from links, which breaks click-to-conversion ties. The result is signal loss before data reaches Meta.

The fix is server side tracking with the Conversions API using a service like PixelFlow, which bypasses those blockers. When events flow from your server instead of the browser, ad blockers cannot touch them.

Issue 2: Weak First-Party Data Capture

If checkout and lead forms do not collect email or phone, you have nothing strong to send, even if CAPI is live. Many teams sit on big lists in a CRM or ESP but never pass those identifiers with purchase or lead events. Think about having ten thousand emails in Klaviyo while sending zero email parameters with your Purchase events. That is money left on the table.

Issue 3: Thin Event Payloads

Sending only IP and user agent gives Meta a blurry picture. Each extra quality parameter, like email or fbc, sharpens the image and improves matching. It is like switching from a fuzzy photo to a high-resolution image with clean metadata that tells the full story.

Issue 4: Technical Errors

Data hashed with the wrong method or in the wrong format will not match. Missing event_id means deduplication fails when Pixel and CAPI both send the same conversion. Misconfigured endpoints drop events entirely.

Common technical mistakes include:

• Using MD5 instead of SHA-256 for hashing

• Forgetting to lowercase and trim email addresses

• Sending phone numbers without country codes

• Not removing special characters from phone numbers

• Missing event_id values for deduplication

• Incorrect test_event_code during testing

PixelFlow removes these gotchas with tested, automated setups, which is a simple way to stop silent failures.

How Can You Improve Your Event Match Quality Score?

A simple plan fixes most setups and raises your score while cutting CPA.

Step 1: Implement Facebook Conversions API

Start with the Facebook Conversions API, also called CAPI. Server-to-server sending avoids ad blockers, ITP, and cookie limits, so events arrive complete even when the Pixel is blocked. Your data flows reliably, your match rate improves, and Meta can attribute more conversions.

You have a few paths to go live:

• Platform integrations like Shopify or WooCommerce

• CAPI Gateway for simpler setup

• Custom server connections for full control

• No-code solutions like PixelFlow for Webflow, Framer, and Squarespace

In the past, this took developer time and weeks of trial and error. That road costs time and cash most teams do not have. PixelFlow makes the Facebook Conversions API simple for Webflow, Framer, and Squarespace without code or Google Tag Manager. In under ten minutes, you can deploy enterprise-grade tracking with automatic deduplication, GDPR-friendly hashing, and event logs you can trust.

Every day your Event Match Quality score stays low, your costs rise and your data stays cloudy. Check your scores in Events Manager now, then see how PixelFlow can take you to 8 and above in days, not months.

Step 2: Capture and Enrich Your First-Party Data

Next, improve the data you collect across forms, checkout, account creation, and newsletter signups. Give simple prompts for email and phone at key steps and consider light incentives such as a small discount or bonus content. Connect your CRM and email platform so you can include known identifiers whenever someone completes a bottom-funnel action.

Practical data collection tips:

• Add email capture at early touchpoints (newsletter popup, content gates)

• Offer incentives for phone number collection (SMS updates, order tracking)

• Use progressive profiling to gather more data over time

• Sync your CRM data with conversion events

• Implement login walls for premium content or tools

Adopt a clear external_id system so each user keeps the same ID across sessions. Use progressive profiling to add more fields over time as trust grows. Even adding hashed email to half of your Purchase events can move the Event Match Quality score from 5 to 7.

PixelFlow makes it easy to enrich events with available parameters from your forms and checkout, which makes this step easy for non-technical teams.

Step 3: Enable Deduplication and Advanced Matching

Run Pixel and CAPI together with clean deduplication. Send the same event_id for the browser and server versions of each conversion so Meta counts one event, not two. PixelFlow automatically loads both your Pixel & CAPI together for perfect event deduplication.

Turn on Automatic Advanced Matching in Pixel settings, which scans key pages for plaintext PII, hashes it in the browser, and adds it to events.

"Deduplication is critical when running both Pixel and CAPI. Without matching event IDs, you'll artificially inflate your conversion counts and confuse Meta's algorithm." — Facebook Business Help Center

Use Test Events in Events Manager to check that parameters arrive and that events show as Deduplicated. PixelFlow handles event_id logic automatically, which removes manual tracking chores.

Additional configuration steps:

• Enable Automatic Advanced Matching in Events Manager

• Verify event_id consistency across Pixel and CAPI

• Test with the Test Events tool before going live

• Monitor the Diagnostics tab for warnings

• Set up custom conversions for specific user flows

How Do You Check and Monitor Your EMQ Score in Facebook Events Manager?

You can view your Event Match Quality score in a few clicks. Go to Business Suite, open All Tools, then Events Manager. Choose your Pixel or dataset, then look at the Overview tab. Each event shows a number like 8.3 out of 10 with a label such as Great, Good, OK, or Poor.

Step-by-Step Monitoring Process

1. Navigate to Events Manager from your Facebook Business Suite

2. Select your Pixel or Conversions API dataset

3. Click the Overview tab to see all events

4. Review EMQ scores next to each event type

5. Click any score to open the diagnostic panel

6. Review missing parameters and specific recommendations

Click any score to open a diagnostic panel. You will see which parameters are missing and get specific tips like "add email" or "add phone." Scores reflect the last 48 hours of data, so allow a couple of days for changes to show. Check your score at least once per week, and always review it after changes to your tracking or site forms.

Setting Realistic EMQ Targets

Set targets by funnel stage:

• Purchases and Leads should aim for 8 or higher

• InitiateCheckout and AddToCart are healthy above 6.5

• ViewContent and PageView can sit near 5 when many visitors are anonymous

Take a quick screenshot of your baseline before changes, then log improvements to show ROI to your team. Track not just the score itself, but also:

• Match rate percentage over time

• Parameter coverage (which fields are present)

• Event volume (number of events firing)

• Cost per action trends as EMQ improves

Real-World Impact: What Happens When You Fix Your EMQ Score

The numbers tell a compelling story. When advertisers move from a poor EMQ score (below 4) to a great score (above 8), several metrics shift:

• Cost per acquisition typically drops 25-45%

• Conversion tracking accuracy improves by 30-60%

• Campaign learning phase completes 40% faster

• Lookalike audience quality increases measurably

• Attribution windows capture more conversions

One PixelFlow user running a Webflow eCommerce store reported their Purchase event EMQ jumping from 3.2 to 9.1 after implementing CAPI with enriched customer parameters. Within two weeks, their cost per purchase dropped by 38% while maintaining the same ad spend, effectively increasing their ROAS by over 60%.