diff --git a/media/base/codec.cc b/media/base/codec.cc
index cb2a8fc3df..be3152aaf3 100644
--- a/media/base/codec.cc
+++ b/media/base/codec.cc
@@ -11,12 +11,12 @@
 #include "media/base/codec.h"
 
 #include <algorithm>
-#include <sstream>
 
 #include "media/base/h264_profile_level_id.h"
 #include "rtc_base/checks.h"
 #include "rtc_base/logging.h"
 #include "rtc_base/stringencode.h"
+#include "rtc_base/strings/string_builder.h"
 #include "rtc_base/stringutils.h"
 
 namespace cricket {
@@ -183,10 +183,11 @@ bool AudioCodec::Matches(const AudioCodec& codec) const {
 }
 
 std::string AudioCodec::ToString() const {
-  std::ostringstream os;
-  os << "AudioCodec[" << id << ":" << name << ":" << clockrate << ":" << bitrate
+  char buf[256];
+  rtc::SimpleStringBuilder sb(buf);
+  sb << "AudioCodec[" << id << ":" << name << ":" << clockrate << ":" << bitrate
      << ":" << channels << "]";
-  return os.str();
+  return sb.str();
 }
 
 webrtc::RtpCodecParameters AudioCodec::ToCodecParameters() const {
@@ -197,9 +198,10 @@ webrtc::RtpCodecParameters AudioCodec::ToCodecParameters() const {
 }
 
 std::string VideoCodec::ToString() const {
-  std::ostringstream os;
-  os << "VideoCodec[" << id << ":" << name << "]";
-  return os.str();
+  char buf[256];
+  rtc::SimpleStringBuilder sb(buf);
+  sb << "VideoCodec[" << id << ":" << name << "]";
+  return sb.str();
 }
 
 webrtc::RtpCodecParameters VideoCodec::ToCodecParameters() const {
@@ -331,9 +333,10 @@ DataCodec& DataCodec::operator=(const DataCodec& c) = default;
 DataCodec& DataCodec::operator=(DataCodec&& c) = default;
 
 std::string DataCodec::ToString() const {
-  std::ostringstream os;
-  os << "DataCodec[" << id << ":" << name << "]";
-  return os.str();
+  char buf[256];
+  rtc::SimpleStringBuilder sb(buf);
+  sb << "DataCodec[" << id << ":" << name << "]";
+  return sb.str();
 }
 
 bool HasNack(const Codec& codec) {
diff --git a/media/base/streamparams.cc b/media/base/streamparams.cc
index 147a5aec91..4c191d5105 100644
--- a/media/base/streamparams.cc
+++ b/media/base/streamparams.cc
@@ -11,9 +11,9 @@
 #include "media/base/streamparams.h"
 
 #include <list>
-#include <sstream>
 
 #include "rtc_base/checks.h"
+#include "rtc_base/strings/string_builder.h"
 
 namespace cricket {
 namespace {
@@ -90,17 +90,18 @@ bool MediaStreams::RemoveDataStream(
 }
 
 static std::string SsrcsToString(const std::vector<uint32_t>& ssrcs) {
-  std::ostringstream ost;
-  ost << "ssrcs:[";
+  char buf[1024];
+  rtc::SimpleStringBuilder sb(buf);
+  sb << "ssrcs:[";
   for (std::vector<uint32_t>::const_iterator it = ssrcs.begin();
        it != ssrcs.end(); ++it) {
     if (it != ssrcs.begin()) {
-      ost << ",";
+      sb << ",";
     }
-    ost << *it;
+    sb << *it;
   }
-  ost << "]";
-  return ost.str();
+  sb << "]";
+  return sb.str();
 }
 
 SsrcGroup::SsrcGroup(const std::string& usage,
@@ -118,12 +119,13 @@ bool SsrcGroup::has_semantics(const std::string& semantics_in) const {
 }
 
 std::string SsrcGroup::ToString() const {
-  std::ostringstream ost;
-  ost << "{";
-  ost << "semantics:" << semantics << ";";
-  ost << SsrcsToString(ssrcs);
-  ost << "}";
-  return ost.str();
+  char buf[1024];
+  rtc::SimpleStringBuilder sb(buf);
+  sb << "{";
+  sb << "semantics:" << semantics << ";";
+  sb << SsrcsToString(ssrcs);
+  sb << "}";
+  return sb.str();
 }
 
 StreamParams::StreamParams() = default;
@@ -134,38 +136,39 @@ StreamParams& StreamParams::operator=(const StreamParams&) = default;
 StreamParams& StreamParams::operator=(StreamParams&&) = default;
 
 std::string StreamParams::ToString() const {
-  std::ostringstream ost;
-  ost << "{";
+  char buf[2 * 1024];
+  rtc::SimpleStringBuilder sb(buf);
+  sb << "{";
   if (!groupid.empty()) {
-    ost << "groupid:" << groupid << ";";
+    sb << "groupid:" << groupid << ";";
   }
   if (!id.empty()) {
-    ost << "id:" << id << ";";
+    sb << "id:" << id << ";";
   }
-  ost << SsrcsToString(ssrcs) << ";";
-  ost << "ssrc_groups:";
+  sb << SsrcsToString(ssrcs) << ";";
+  sb << "ssrc_groups:";
   for (std::vector<SsrcGroup>::const_iterator it = ssrc_groups.begin();
        it != ssrc_groups.end(); ++it) {
     if (it != ssrc_groups.begin()) {
-      ost << ",";
+      sb << ",";
     }
-    ost << it->ToString();
+    sb << it->ToString();
   }
-  ost << ";";
+  sb << ";";
   if (!cname.empty()) {
-    ost << "cname:" << cname << ";";
+    sb << "cname:" << cname << ";";
   }
-  ost << "stream_ids:";
+  sb << "stream_ids:";
   for (std::vector<std::string>::const_iterator it = stream_ids_.begin();
        it != stream_ids_.end(); ++it) {
     if (it != stream_ids_.begin()) {
-      ost << ",";
+      sb << ",";
     }
-    ost << *it;
+    sb << *it;
   }
-  ost << ";";
-  ost << "}";
-  return ost.str();
+  sb << ";";
+  sb << "}";
+  return sb.str();
 }
 void StreamParams::GetPrimarySsrcs(std::vector<uint32_t>* ssrcs) const {
   const SsrcGroup* sim_group = get_ssrc_group(kSimSsrcGroupSemantics);
diff --git a/media/base/videocommon.cc b/media/base/videocommon.cc
index e5168b55ca..7c81eeb98f 100644
--- a/media/base/videocommon.cc
+++ b/media/base/videocommon.cc
@@ -12,9 +12,9 @@
 
 #include <limits.h>  // For INT_MAX
 #include <math.h>
-#include <sstream>
 
 #include "rtc_base/arraysize.h"
+#include "rtc_base/strings/string_builder.h"
 
 namespace cricket {
 
@@ -70,10 +70,11 @@ std::string VideoFormat::ToString() const {
     }
   }
 
-  std::ostringstream ss;
-  ss << fourcc_name << width << "x" << height << "x"
+  char buf[256];
+  rtc::SimpleStringBuilder sb(buf);
+  sb << fourcc_name << width << "x" << height << "x"
      << IntervalToFpsFloat(interval);
-  return ss.str();
+  return sb.str();
 }
 
 }  // namespace cricket
diff --git a/rtc_base/strings/string_builder.cc b/rtc_base/strings/string_builder.cc
index 528f099560..70a14da4ca 100644
--- a/rtc_base/strings/string_builder.cc
+++ b/rtc_base/strings/string_builder.cc
@@ -67,15 +67,15 @@ SimpleStringBuilder& SimpleStringBuilder::operator<<(
 }
 
 SimpleStringBuilder& SimpleStringBuilder::operator<<(float f) {
-  return AppendFormat("%f", f);
+  return AppendFormat("%g", f);
 }
 
 SimpleStringBuilder& SimpleStringBuilder::operator<<(double f) {
-  return AppendFormat("%f", f);
+  return AppendFormat("%g", f);
 }
 
 SimpleStringBuilder& SimpleStringBuilder::operator<<(long double f) {
-  return AppendFormat("%Lf", f);
+  return AppendFormat("%Lg", f);
 }
 
 SimpleStringBuilder& SimpleStringBuilder::AppendFormat(const char* fmt, ...) {
diff --git a/rtc_base/strings/string_builder_unittest.cc b/rtc_base/strings/string_builder_unittest.cc
index 8d6312f947..aa570ebbb8 100644
--- a/rtc_base/strings/string_builder_unittest.cc
+++ b/rtc_base/strings/string_builder_unittest.cc
@@ -33,7 +33,7 @@ TEST(SimpleStringBuilder, NumbersAndChars) {
   SimpleStringBuilder sb(sb_buf);
   sb << 1 << ':' << 2.1 << ":" << 2.2f << ':' << 78187493520ll << ':'
      << 78187493520ul;
-  EXPECT_EQ(0, strcmp(sb.str(), "1:2.100000:2.200000:78187493520:78187493520"));
+  EXPECT_EQ(0, strcmp(sb.str(), "1:2.1:2.2:78187493520:78187493520"));
 }
 
 TEST(SimpleStringBuilder, Format) {