From version 30.x, Protobuf DebugString APIs (Message::DebugString, Message::ShortDebugString, Message::Utf8DebugString), additional Protobuf APIs (proto2::ShortFormat, proto2::Utf8Format), Abseil string functions (such as absl::StrCat, absl::StrFormat, absl::StrAppend, and absl::Substitute), and Abseil logging API will begin to automatically convert proto arguments into a new debugging format . See the related announcement here. Unlike the Protobuf DebugString output format, the new debugging format automatically redacts sensitive fields by replacing their values with the string “[REDACTED]” (without the quotation marks).