diff --git a/.changeset/efficiently-splitCssText-1640.md b/.changeset/efficiently-splitCssText-1640.md
new file mode 100644
index 0000000000..57c6d5e6c4
--- /dev/null
+++ b/.changeset/efficiently-splitCssText-1640.md
@@ -0,0 +1,6 @@
+---
+"rrweb-snapshot": patch
+"rrweb": patch
+---
+
+Improve performance of splitCssText for <style> elements with large css content - see #1603