List of largest nebulae

Below is a list of the largest known nebulae so far discovered, ordered by actual diameter. This list is prone to change because of inconsistencies between studies, the great distances of nebulae from our stellar neighborhood, and the constant refinement of technology and engineering.

Caveats
Nebulae have no standardized boundaries, so the measurements are subject to revision. Lastly, scientists are still defining the features and parameters of nebulae. Because of these rapid developments and adjustments, this list might be potentially unreliable.