How do I fix incorrect data?

If you just missed adding something, you can just add the new data like normal, adjusting the date to enter it on.

If you need to edit a datapoint, then this depends on platform:

• On web: find the incorrect datapoint in the "Data" tab below the graph, and then change the details you want to change there. Press update to submit the change. There's no way to update multiple datapoints at a time, so it's best to click the update button for each change you make so you don't forget to submit your changes!
• On Android: you can edit datapoints by tapping on the bulletpoint list icon at the top right, and then tapping the entry you want to edit. Make your change, and then tap "Update".
• On iOS: tap the datapoint you want to edit in the list of recent datapoints to open the edit window, make your changes, and then tap "Update".

You can also delete datapoints using the Delete button on all platforms, though you should do this with extreme caution. Deleting data may trigger an immediate derailment on your graph, because removing old datapoints can change whether you're on the right side of the bright red line at your last deadline, due to the cumulative graph. Sometimes you may want to do this on purpose if you realize you should have derailed, of course!

Bear in mind that this advice mostly applies to manual goals. Goals which receive automatic data need to be updated/edited via the data source, and in some cases it isn't possible to change historical data.

I edited my data on Beeminder, but it reverted back to what it was before!

If your goal uses an automatic data source, Beeminder will usually refetch the original data from the data source and overwrite your changes. It's not that we don't trust you (well, possibly that too; lots of people use autodata goals precisely because they don't trust themselves!) but we need a single ground truth for the data so if the autodata source changes, Beeminder updates the data to match. Otherwise, strange conflicts can arise, data gets double-entered, etc.

To update most autodata-fed goals, you need to change the data at the source (e.g. in Fitbit or Toggl or whichever service the graph is linked up with), then click the button on the Beeminder goal page to refresh/refetch it.

Keywords: editing data, editing old data, update data