Comparing your data with a previous period can be useful to show your client how their campaigns, ads, tweets, etc. are performing over time. To enable comparison in a widget, go to the "Date range" tab and select the comparison date range you want to use for the widget:

On the upper part of the report, you can find the report's date range. There you'll be able to select a comparison date range that will apply to all widgets in your report that have comparison enabled.

There are a few different options to choose from:

This setting is only available in widgets. With this setting the widget will use the comparison setting from the report.

Note: When using shareable linked reports, this is the only comparison setting that changes along when the comparison date range is changed. Widgets with any of the other settings will not be influenced by changes to the overall comparison date range. They will continue using the comparison date range set up in the widget.

This option compares to the previous period, using the exact amount of days in your date range. So if your date range is June 11-20, 10 days, your compare date range would be June 1-10.

This option compares to the previous period, however contrary to the "previous period" option this one takes into account that you want to compare two entities. This option is perfect when you want to compare month-on-month. 

Take for example May and June. May contains 31 days, while June contains only 30. If your report date range is June, the previous period option would compare with exactly 30 days (May 2-31). The previous month option will, however, compare the entirety of May with June, ignoring that May has a day extra.

With this you can compare a period with the exact same period in the previous year. This is for example good for seasonal reports, where you want to compare the statistics during holiday times with how they were the previous year.

This allows you to enter a custom period as a comparison period. As for this the number of days needs to be the same as the amount in the report date range, you'll only be asked to choose a start date when using this option. We then calculate what the end date is, based on the selected report date range, which is also visualized in the start date selector.

In KPIs comparison is visualized as a percentage change with red or green arrow pointing either upwards or downwards. This indicates whether the value went up or down in comparison to the comparison date range and whether this is a good or bad thing.

When enabling comparison in charts, an extra line is added for each metric in the KPI. The light color will always represent the comparison data.

Comparison in tables allows you to compare multiple metrics for a specified dimension.

There are several dimensions for which comparing in tables is not yet supported. Comparing time dimensions (e.g. "Month") or breakdown dimensions is currently not available, but will be addressed in upcoming versions of the feature.