'StringBuilder' can be replaced with 'String'

Reports usages of StringBuffer, StringBuilder, or StringJoiner which can be replaced with a single String concatenation.

Using String concatenation makes the code shorter and simpler.

This inspection only reports when the suggested replacement does not result in significant performance drawback on modern JVMs. In many cases, String concatenation may perform better.

Example:

  StringBuilder result = new StringBuilder();
  result.append("i = ");
  result.append(i);
  result.append(";");
  return result.toString();

After the quick-fix is applied:

  String result = "i = " + i + ";";
  return result;

Locating this inspection

By ID

Can be used to locate inspection in e.g. Qodana configuration files, where you can quickly enable or disable it, or adjust its settings.

StringBufferReplaceableByString

Via Settings dialog

Path to the inspection settings via IntelliJ Platform IDE Settings dialog, when you need to adjust inspection settings directly from your IDE.

Settings or Preferences | Editor | Inspections | Java | Verbose or redundant code constructs

Suppressing Inspection

You can suppress this inspection by placing the following comment marker before the code fragment where you no longer want messages from this inspection to appear:

//noinspection StringBufferReplaceableByString

More detailed instructions as well as other ways and options that you have can be found in the product documentation:

IntelliJ IDEA 2025.2

Inspection Details
By default bundled with:	IntelliJ IDEA 2025.2, Qodana for JVM 2025.2,

Last modified: 18 September 2025