diff --git a/api/docs/release.dox b/api/docs/release.dox
index d9cc6aefb0f..759ecade1ef 100644
--- a/api/docs/release.dox
+++ b/api/docs/release.dox
@@ -129,7 +129,8 @@ changes:
  - No compatibility changes yet.
 
 Further non-compatibility-affecting changes include:
- - Nothing yet.
+ - Added support for reading a single drmemtrace trace file from stdin
+   via "-infile -".
 
 **************************************************
 <hr>
diff --git a/clients/drcachesim/common/options.cpp b/clients/drcachesim/common/options.cpp
index 58047dd40ad..cebeca16504 100644
--- a/clients/drcachesim/common/options.cpp
+++ b/clients/drcachesim/common/options.cpp
@@ -1,5 +1,5 @@
 /* **********************************************************
- * Copyright (c) 2015-2024 Google, Inc.  All rights reserved.
+ * Copyright (c) 2015-2025 Google, Inc.  All rights reserved.
  * **********************************************************/
 
 /*
@@ -95,9 +95,14 @@ droption_t<std::string> op_indir(
     "delete files here.");
 
 droption_t<std::string> op_infile(
-    DROPTION_SCOPE_ALL, "infile", "", "Offline legacy file for input to the simulator",
-    "Directs the simulator to use a single all-threads-interleaved-into-one trace file. "
-    "This is a legacy file format that is no longer produced.");
+    DROPTION_SCOPE_ALL, "infile", "", "Single offline trace input file",
+    "Directs the framework to use a single trace file.  This could be a legacy "
+    "all-software-threads-interleaved-into-one trace file, a core-sharded single "
+    "hardware thread file mixing multiple software threads, or a single software "
+    "thread selected from a directory (though in that case it is better to use "
+    "-only_thread, -only_threads, or -only_shards).  This method of input does "
+    "not support any features that require auxiliary metadata files. "
+    "Passing '-' will read from stdin as plain or gzip-compressed data.");
 
 droption_t<int> op_jobs(
     DROPTION_SCOPE_ALL, "jobs", -1, "Number of parallel jobs",
diff --git a/clients/drcachesim/reader/compressed_file_reader.cpp b/clients/drcachesim/reader/compressed_file_reader.cpp
index 5007f558631..9e441c1adab 100644
--- a/clients/drcachesim/reader/compressed_file_reader.cpp
+++ b/clients/drcachesim/reader/compressed_file_reader.cpp
@@ -1,5 +1,5 @@
 /* **********************************************************
- * Copyright (c) 2017-2023 Google, Inc.  All rights reserved.
+ * Copyright (c) 2017-2025 Google, Inc.  All rights reserved.
  * **********************************************************/
 
 /*
@@ -52,7 +52,14 @@ namespace drmemtrace {
 bool
 open_single_file_common(const std::string &path, gzFile &out)
 {
-    out = gzopen(path.c_str(), "rb");
+    if (path == "-") {
+        // We assume stdin is 0.
+        // We do not use the glibc-specific "stdin->_fileno" method of finding the
+        // stdin descriptor number as that is not portable to musl or other libc.
+        constexpr int STDIN_FD = 0;
+        out = gzdopen(STDIN_FD, "rb");
+    } else
+        out = gzopen(path.c_str(), "rb");
     return out != nullptr;
 }
 
diff --git a/clients/drcachesim/tests/offline-stdin.expect b/clients/drcachesim/tests/offline-stdin.expect
new file mode 100644
index 00000000000..0ada73ad6e0
--- /dev/null
+++ b/clients/drcachesim/tests/offline-stdin.expect
@@ -0,0 +1,16 @@
+Output format:
+<--record#-> <--instr#->: <---tid---> <record details>
+------------------------------------------------------------
+           1           0:     1257596 <marker: version 4>
+           2           0:     1257596 <marker: filetype 0x10e40>
+           3           0:     1257596 <marker: cache line size 64>
+           4           0:     1257596 <marker: chunk instruction count 10000000>
+           5           0:     1257596 <marker: page size 4096>
+           6           0:     1257596 <marker: timestamp 13331862027607247>
+           7           0:     1257596 <marker: tid 1257596 on core 8>
+           8           1:     1257596 ifetch       4 byte\(s\) @ 0x00007f3e429fce35 48 8b 45 f8          mov    -0x08\(%rbp\), %rax
+           9           1:     1257596 read         8 byte\(s\) @ 0x00007ffefb03e128 by PC 0x00007f3e429fce35
+          10           2:     1257596 ifetch       8 byte\(s\) @ 0x00007f3e429fce39 48 8d 14 c5 00 00 00 lea    0x00\(,%rax,8\), %rdx
+          10           2:     1257596                                             00
+View tool results:
+              2 : total instructions
diff --git a/suite/tests/CMakeLists.txt b/suite/tests/CMakeLists.txt
index 357f60c3f82..9b92963b0df 100644
--- a/suite/tests/CMakeLists.txt
+++ b/suite/tests/CMakeLists.txt
@@ -4006,6 +4006,28 @@ if (BUILD_CLIENTS)
           # Avoid the default core-sharded from re-scheduling the trace.
           "-indir ${core_sharded_dir} -tool schedule_stats -only_shards 2,3 -no_core_sharded" "")
         set(tool.core_on_disk_rawtemp ON) # no preprocessor
+
+        # Test reading a file over stdin.
+        # We rely on there being just one subfile in this zip file: gunzip only
+        # extracts the first one (bsdtar can extract all but is not likely installed).
+        # This is UNIX only so we rely on cat and gunzip being available.
+        find_program(CAT_EXE cat DOC "path to cat")
+        find_program(GUNZIP_EXE gunzip DOC "path to gunzip")
+        find_program(BASH_EXE bash DOC "path to bash")
+        if (CAT_EXE AND GUNZIP_EXE AND BASH_EXE)
+          # Easiest to make our pipeline in bash with a direct add_test()
+          # (although this bypasses the torun() features used by all other tests).
+          set(infile "${core_sharded_dir}/drmemtrace.core.0.trace.zip")
+          add_test(tool.drcacheoff.stdin
+            ${BASH_EXE} -c
+            "${CAT_EXE} ${infile} | ${GUNZIP_EXE} | ${drrun_path} -t drmemtrace -tool view -sim_refs 10 -infile -")
+          file(READ "${PROJECT_SOURCE_DIR}/clients/drcachesim/tests/offline-stdin.expect"
+            stdin_expect)
+          set_tests_properties(tool.drcacheoff.stdin PROPERTIES
+            PASS_REGULAR_EXPRESSION "${stdin_expect}")
+        else ()
+          message("Failed to find cat, gunzip, and bash: not running stdin test")
+        endif ()
       endif ()
     endif ()