Comparing Scans
Walk through picking two scans, filtering the results, drilling into a single resource's property diff, and silencing a noisy field with an ignore rule. Open Changes from the left sidebar.
On This Page
Ignore rules are tenant-wide
Adding or removing a rule affects every user's view, every comparison, and every future scan. Remove with care.
Pick the Comparison Range
- The page opens with the two most recent scans pre-selected. Latest is the Newer Snapshot, second-latest is the Older Snapshot.
- Click Older Snapshot to choose a different baseline. The dropdown hides scans newer than the current Newer pick, and it never lets you pick the latest scan as the Older Snapshot.
- Click Newer Snapshot to choose a different comparison scan. The dropdown hides scans older than the current Older pick.
Pick a long range for incident retros
The Older Snapshot doesn't have to be the previous scan, you can compare today against a scan from six months ago.
Filter and Reshape Results
Three controls live above the result list:
- Change Type
- Multi-select. Deselect Added, Modified, or Deleted to hide that type. Defaults to all three selected.
- Show Ignored
- Affects both the resource list and the property diff inside each resource. Off by default.
- View Mode
- Subscription, Resource Type, Region, or Region by RG. Same selector as the Resource Explorer; selection persists per-page.
The Property Diff
Click any resource in the list to expand its property diff. The diff is a three-column table:
- Property
- The property path (for example,
properties.hardwareProfile.vmSize). - Old Value
- Value at the Older Snapshot.
- New Value
- Value at the Newer Snapshot.
Row colors signal change type: green for added, red for deleted, no fill for modified. Ignored rows render with muted text and the literal word Ignored in both value columns when Show Ignored is on.
Wrap long values
A Wrap all checkbox above the diff table wraps long values onto multiple lines instead of truncating them, useful when comparing complex configuration values.
Hide a Noisy Property
At the right edge of every property row, an eye-slash icon adds an ignore rule. Click it to open a popover with three scope options:
Ignore for All Types
Global rule. Applies to every Azure resource type. Reach for this only when the field truly appears identically everywhere (for example, etag).
Ignore for {ResourceType} Only
Limits the rule to the current resource's exact type (for example, Microsoft.Compute/virtualMachines). The most predictable scope, recommended as a default.
Ignore field name everywhere
Ignores any field with this name regardless of where it appears. For example, choosing this on a VM's size field ignores any field called vmSize on every resource.
Default to {ResourceType} Only
It's the most predictable scope. Reach for All Types only for fields that are truly universal noise.
Rules cover every item in a list
When you add a rule for a property inside a list (for example, a subnet's address prefix), the rule applies to every item in that list, not just the one you clicked on.
Rules apply to future scans too
Ignore rules apply both to the diff you're viewing now and to every future scan. A resource that only changes in ignored fields won't show up as Modified.
Un-Hide a Property
Turn on Show Ignored to surface ignored rows. Each ignored row shows an eye icon at the right edge, click it and confirm to remove the rule.
Removal is immediate, no undo
A small popover asks Remove this rule? with a single Confirm button. There is no undo other than re-adding the rule.
For bulk rule cleanup, jump to Settings > Ignore List instead.
Ignore Metrics Analysis
When at least one change in the comparison range is ignored, a {N} changes ignored button appears in the page header. Click it to open the Ignore Metrics Analysis modal.
The modal aggregates filtered noise across every scan that fell inside the comparison range, not just the two endpoints. That's why the count can be much higher than the diff itself.
The modal has two tabs:
- Resources, ranked by how many ignored changes fired against them across the range.
- Rules, showing which of your ignore rules pulled the most weight.
A summary card highlights High Frequency Resources, resources whose change frequency exceeded half of the scans analyzed. These are the resources that flip on every scan (for example, a service that always reports provisioningState: Updating mid-run).
Bookmarking and Sharing
Your snapshot picks, view mode, change-type filter, and Show Ignored toggle all live in the page URL. Bookmark a comparison or share the link with a teammate, they'll land on the exact same view.
Troubleshooting
I added an ignore rule but the property is still showing
What to check
Confirm Show Ignored is off. When it's on, ignored rows still render (with Ignored in both value columns) so you can verify rules are working.
The rule I added covers a different field too
What to check
You probably picked Ignore field name everywhere, which matches every property with that field name regardless of where it lives. Remove it and re-add as Ignore for {ResourceType} Only for tighter scope.
I see "Ignored" in the value columns of a row I didn't add a rule for
What to check
That's a default rule, or a rule another user added. Click the eye icon to remove it inline, or open Settings > Ignore List to inspect the full rule list.
My filter changes don't survive a page refresh
What to check
They should, all filter state lives in the URL. If a refresh wipes them, copy the URL before refreshing and paste it back.