FeatureSignals

Target Comparison

Compare how two different users evaluate for the same flag. See exactly which rules match or don't match for each user side-by-side, so you can understand why they receive different variations.

What It Does

The Target Comparison tool extends the Target Inspector by letting you compare two users simultaneously. This is invaluable when:

  • One user sees the feature but another doesn't, and you need to understand why
  • You want to verify that a targeting rule correctly distinguishes between user groups
  • You're testing a new targeting rule and want to confirm it affects the right users
  • You're debugging a percentage rollout and need to check two specific user keys

Using Target Comparison

To use Target Comparison, open any flag's detail page and click the Comparetab within the Inspect panel. You'll see:

  1. User A and User B inputs — Enter the key and attributes for each user. You can also paste JSON attribute objects for quick entry.
  2. Side-by-side rule matrix — Each targeting rule is displayed with match results for both users. Differences are highlighted for quick identification.
  3. Diff summary — A summary card shows whether the two users receive the same variation or different ones, and which rule caused the divergence.

Comparison Example

Here's an example comparing two users evaluating the new-checkout flag:

User Auser-123
email: alice@company.com · country: US · tier: enterprise
Enterprise Customers
US Rollout 50%
Default
Result: ON (v2 checkout)
User Buser-789
email: bob@startup.io · country: DE · tier: starter
Enterprise Customers
US Rollout 50%
Default
Result: OFF (v1 checkout)

User A matches the "Enterprise Customers" rule (tier=enterprise) and gets v2. User B doesn't match any rule and falls through to the default, getting v1.

Diff Summary

The diff summary highlights exactly where the two users diverge:

Users diverge at Rule 1: "Enterprise Customers"
  • User A has tier=enterprise, which matches the segment definition. Rule applies → v2 served.
  • User B has tier=starter, which does not match. Rule skipped → falls through to default → v1 served.

When to Use Target Comparison

Testing new targeting rules

Before enabling a new targeting rule in production, compare a user who should match against one who shouldn't. Verify the rule behaves as expected.

Debugging user-reported issues

When a user reports they can't access a feature, compare their evaluation against a known-good user to quickly identify the difference.

Validating segment definitions

Compare two users with different attribute values to confirm your segment conditions correctly include and exclude the right users.

Rollout verification

For percentage rollouts, compare two users to confirm they fall into the expected buckets based on the hash assignment.

Next Steps