Could not resolve comparator for sort key sort – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 6.8-7.17

Briefly, this error occurs when Elasticsearch is unable to find a suitable comparator for the specified sort key. This could be due to a non-existent field, incorrect field name, or a field type that doesn’t support sorting. To resolve this issue, ensure that the field you’re trying to sort by exists in your index and is of a sortable type. Also, check for any typographical errors in the field name. If the field type is not sortable, consider changing it to a type that supports sorting.

This guide will help you check for common problems that cause the log ” Could not resolve comparator for sort key: [” + sort + “] ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: sort, search.

Log Context

Log “Could not resolve comparator for sort key: [” + sort + “]” class name is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 case SCORE:
 return SCORE;
 return FREQUENCY;
 throw new ElasticsearchException("Could not resolve comparator for sort key: [" + sort + "]");
 }  @Override
 public void writeTo(StreamOutput out) throws IOException {


How helpful was this guide?

We are sorry that this post was not useful for you!

Let us improve this post!

Tell us how we can improve this post?