What event match quality is
When your site sends a conversion to Meta's Conversions API, Meta tries to match it to a person with a Meta account. Event match quality (EMQ) is Meta's score, out of 10, for how well the customer details on an event let it do that. You'll find it in Events Manager, for each event your server sends.
A conversion Meta can't match to anyone can't be credited to the ad they clicked, and can't teach the delivery system who converts. So a better match usually means better reporting and better optimisation. Meta doesn't publish how the score is calculated, so treat it as a guide, not a target.
The details that matter
Meta calls these customer information parameters. Roughly from most to least useful for a typical lead-gen site:
| Detail | Meta's key | Where it comes from |
|---|---|---|
| Email, hashed | em | A form field |
| Phone, hashed | ph | A form field, with the country code |
| Click ID | fbc | The fbclid on the ad's landing page address |
| Browser ID | fbp | The cookie Meta's pixel sets |
| IP address and browser | client_ip_address, client_user_agent | The visitor's request |
| First and last name, hashed | fn, ln | Form fields |
| Your own customer ID, hashed | external_id | Your system, if you have one |
Emails, phone numbers and names must be normalised (trimmed, lowercased, phone numbers as digits with the country code) and hashed with SHA-256 before they're sent. A detail hashed the wrong way doesn't match, so it doesn't help.
How to improve it
- Send the email and phone from your forms. These do the most for lead events. Ask for a phone number only if you need it.
- Keep the click ID. When someone lands from an ad, the
fbclidin the address should become anfbcvalue on every later event in that visit, not just the first page. - Send IP address and browser from the server side. A server event without them is much harder to match.
- Run the pixel as well as the Conversions API, with a shared event ID. The pixel sets the
fbpbrowser ID, and the two copies can be deduplicated. - Normalise before hashing.
Jane@Example.comandjane@example.comhash to different values. Only the second one matches. - Don't send what you don't need. Messages and other free text don't help matching, and sending them is a privacy risk.
Good to know
- The score takes time to appear on a new or quiet pixel, and it can move from day to day.
- A visitor's very first page view can't carry
fbp, because the pixel hasn't set it yet. - If your site needs consent, events from visitors who refuse aren't sent at all, so they don't count towards the score either way.
- TikTok has its own match quality rating in its Events Manager, built on similar details: hashed email and phone, its click ID (
ttclid) and IP address.