diff --git a/.chloggen/elasticsearchexporter_sync-bulk-indexer-flush-bytes.yaml b/.chloggen/elasticsearchexporter_sync-bulk-indexer-flush-bytes.yaml
index 74cec1fe274f..979d80bdfad8 100644
--- a/.chloggen/elasticsearchexporter_sync-bulk-indexer-flush-bytes.yaml
+++ b/.chloggen/elasticsearchexporter_sync-bulk-indexer-flush-bytes.yaml
@@ -1,13 +1,13 @@
 # Use this changelog template to create an entry for release notes.
 
 # One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
-change_type: enhancement
+change_type: breaking
 
 # The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
 component: elasticsearchexporter
 
 # A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
-note: Respect `flush::bytes` in sync bulk indexer
+note: Respect `flush::bytes` in sync bulk indexer, `flush::bytes` measures uncompressed size, change default `batcher::max_size_items` to `0`
 
 # Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
 issues: [36163]
@@ -18,6 +18,8 @@ issues: [36163]
 subtext:
   Limit the bulk request size to roughly `flush::bytes` for sync bulk indexer.
   Sync bulk indexer is used when `batcher::enabled` is either true or false. In order words, sync bulk indexer is not used when batcher config is undefined.
+  Change `flush::bytes` to always measure in uncompressed bytes.
+  Change default `batcher::max_size_items` to `0` as bulk request size limit is now more effectively enforced by `flush::bytes`.
 
 # If your change doesn't affect end users or the exported elements of any package,
 # you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
diff --git a/exporter/elasticsearchexporter/README.md b/exporter/elasticsearchexporter/README.md
index fd7321ffb111..391debba8a1a 100644
--- a/exporter/elasticsearchexporter/README.md
+++ b/exporter/elasticsearchexporter/README.md
@@ -91,7 +91,7 @@ The Elasticsearch exporter supports the [common `batcher` settings](https://gith
 - `batcher`:
   - `enabled` (default=unset): Enable batching of requests into a single bulk request.
   - `min_size_items` (default=5000): Minimum number of log records / spans in the buffer to trigger a flush immediately.
-  - `max_size_items` (default=10000): Maximum number of log records / spans in a request.
+  - `max_size_items` (default=0): Maximum number of log records / spans in a request.
   - `flush_timeout` (default=30s): Maximum time of the oldest item spent inside the buffer, aka "max age of buffer". A flush will happen regardless of the size of content in buffer.
 
 By default, the exporter will perform its own buffering and batching, as configured through the
diff --git a/exporter/elasticsearchexporter/config_test.go b/exporter/elasticsearchexporter/config_test.go
index bc803173440b..f3f848db2c90 100644
--- a/exporter/elasticsearchexporter/config_test.go
+++ b/exporter/elasticsearchexporter/config_test.go
@@ -118,7 +118,7 @@ func TestConfig(t *testing.T) {
 						MinSizeItems: 5000,
 					},
 					MaxSizeConfig: exporterbatcher.MaxSizeConfig{
-						MaxSizeItems: 10000,
+						MaxSizeItems: 0,
 					},
 				},
 			},
@@ -190,7 +190,7 @@ func TestConfig(t *testing.T) {
 						MinSizeItems: 5000,
 					},
 					MaxSizeConfig: exporterbatcher.MaxSizeConfig{
-						MaxSizeItems: 10000,
+						MaxSizeItems: 0,
 					},
 				},
 			},
@@ -262,7 +262,7 @@ func TestConfig(t *testing.T) {
 						MinSizeItems: 5000,
 					},
 					MaxSizeConfig: exporterbatcher.MaxSizeConfig{
-						MaxSizeItems: 10000,
+						MaxSizeItems: 0,
 					},
 				},
 			},
diff --git a/exporter/elasticsearchexporter/factory.go b/exporter/elasticsearchexporter/factory.go
index e79883d99962..4783d430196a 100644
--- a/exporter/elasticsearchexporter/factory.go
+++ b/exporter/elasticsearchexporter/factory.go
@@ -91,7 +91,7 @@ func createDefaultConfig() component.Config {
 				MinSizeItems: 5000,
 			},
 			MaxSizeConfig: exporterbatcher.MaxSizeConfig{
-				MaxSizeItems: 10000,
+				MaxSizeItems: 0,
 			},
 		},
 		Flush: FlushSettings{