Compare From Baselines

Compare From is one of the most important Alert Relay inputs.

It tells the connector what earlier version, token, or point in time should be used as the comparison baseline.

Why Compare From matters

Without a useful baseline, a flow may not produce the comparison you expect.

The right Compare From value helps Alert Relay answer questions like:

• what changed since the trigger fired
• what changed since a specific version
• what changed since a specific date

Recommended option for most flows

For most trigger-based SharePoint flows, use:

• TriggerWindowStartToken

This is usually the best default because it aligns the comparison with the SharePoint trigger's own change window.

Supported Compare From values

Alert Relay accepts:

• TriggerWindowStartToken from the SharePoint trigger
• a raw SharePoint change token
• a version label such as 5.0
• an ISO 8601 date such as 2026-03-30
• an ISO 8601 date-time such as 2026-03-30T14:15:00Z

If Compare From is blank

If you leave it blank, Alert Relay uses the first version in the item's version history as the comparison baseline.

Which first version it uses depends on the Include Minor Versions setting:

• if Include Minor Versions is off, Alert Relay uses the first major version
• if Include Minor Versions is on, Alert Relay uses the first version in the full version history

This can work, but for most trigger-driven alert flows TriggerWindowStartToken gives a clearer comparison starting point.

Date-only values

If you provide a date only, such as 2026-03-30, Alert Relay treats it as:

• midnight in the selected Timezone, or
• midnight UTC if no timezone is supplied

What happens if the baseline is out of range

Alert Relay clamps the baseline if needed:

• if the baseline is earlier than the first available version, the comparison uses the first version
• if the baseline is later than the latest version, the comparison uses the current version

This helps prevent impossible comparisons, but it can affect how the result looks.

Common use cases

Standard trigger-driven alerting

Use:

• TriggerWindowStartToken

Example:

• send an email whenever a list item is updated, and compare the update against the trigger's own change window

Compare against a known release or snapshot

Use:

• a version label
• or an ISO date/date-time

Example:

• compare the current document against version 5.0
• compare all later changes against a specific date such as 2026-03-30

Example: Go-live cutover logic

Use:

• Parse Compare From first
• then decide whether to keep the token or use an explicit baseline date

Example:

• if the trigger token is earlier than the launch date of your flow, compare from the launch date instead

When the result covers more than one edit

Sometimes a result includes the net changes across several versions, not just the last single edit.

This often happens when a user updates the same SharePoint item several times in quick succession.

SharePoint creates a version for each edit.

If that happens before your flow action runs, Alert Relay can compare from the resolved baseline version to the latest visible version, rather than showing only the very last edit on its own.

For example:

• the trigger token resolves the baseline to version 9.0
• the latest visible version when the action runs is 16.0
• the action compares 9.0 -> 16.0

Recheck Compare From if:

• Previous Version Label (previousVersionLabel) is older than you expected
• the result includes a wider set of changes than the latest edit alone
• you expected a single-step comparison, but the output spans several versions
• you need the comparison to start from a specific date or version instead of the trigger window

Related pages

• Use Detailed JSON Changes
• Parse Compare From
• Troubleshooting