The input JSON data is malformed – How to solve this Elasticsearch exception

Opster Team

August-23, Version: 6.8-8.9

Briefly, this error occurs when the JSON data sent to Elasticsearch is not correctly formatted or structured. This could be due to missing or extra commas, brackets, or quotes. To resolve this issue, you can use a JSON validator to check and correct the syntax of your JSON data. Alternatively, you can manually review your JSON data to ensure it adheres to the correct structure and syntax. Also, ensure that all strings are properly quoted and special characters are correctly escaped.

This guide will help you check for common problems that cause the log ” The input JSON data is malformed. ” to appear. To understand the issues related to this log, read the explanation below about the following Elasticsearch concepts: plugin.

Log Context

Log “The input JSON data is malformed.” class name is We extracted the following from Elasticsearch source code for those seeking an in-depth context :

 token = parser.nextToken();
 } catch (XContentEOFException | XContentParseException e) {
 if (errorCounter >= PARSE_ERRORS_LIMIT) {
 logger.error("Failed to recover from malformed JSON data."; e);
 throw new ElasticsearchParseException("The input JSON data is malformed.");
 } while (token != XContentParser.Token.END_OBJECT);