The default character limit for a text/string field is 255. You can change it when creating the field, in most moments when you create the field.
All good re form, most data entry is restricted by the length of the field itself. Survey123 can add another layer.
You can't extend a field length. You can only create a new field. If you are in Pro, you need to:
- Backup your data
- Create a new, temporary field
- Field calculate the data from your current field to the new one
- Delete the original field
- Create a new field of the same name, but increase the length
- Field calculate the data from the temp field to the re-created one
- Delete the temp field.
You don't need to do the long workaround if you have not collected any data.
https://pro.arcgis.com/en/pro-app/latest/help/data/geodatabases/overview/modifying-field-properties....
Are you using a feature class in a file geodatabase?