diff --git a/okhttp-logging-interceptor/src/main/java/okhttp3/logging/HttpLoggingInterceptor.java b/okhttp-logging-interceptor/src/main/java/okhttp3/logging/HttpLoggingInterceptor.java
index 5e738b341..532b80ce4 100644
--- a/okhttp-logging-interceptor/src/main/java/okhttp3/logging/HttpLoggingInterceptor.java
+++ b/okhttp-logging-interceptor/src/main/java/okhttp3/logging/HttpLoggingInterceptor.java
@@ -15,6 +15,7 @@
  */
 package okhttp3.logging;
 
+import java.io.EOFException;
 import java.io.IOException;
 import java.nio.charset.Charset;
 import java.nio.charset.UnsupportedCharsetException;
@@ -192,10 +193,14 @@ public final class HttpLoggingInterceptor implements Interceptor {
         }
 
         logger.log("");
-        logger.log(buffer.readString(charset));
-
-        logger.log("--> END " + request.method()
-            + " (" + requestBody.contentLength() + "-byte body)");
+        if (isPlaintext(buffer)) {
+          logger.log(buffer.readString(charset));
+          logger.log("--> END " + request.method()
+              + " (" + requestBody.contentLength() + "-byte body)");
+        } else {
+          logger.log("--> END " + request.method() + " (binary "
+              + requestBody.contentLength() + "-byte body omitted)");
+        }
       }
     }
 
@@ -239,6 +244,12 @@ public final class HttpLoggingInterceptor implements Interceptor {
           }
         }
 
+        if (!isPlaintext(buffer)) {
+          logger.log("");
+          logger.log("<-- END HTTP (binary " + buffer.size() + "-byte body omitted)");
+          return response;
+        }
+
         if (contentLength != 0) {
           logger.log("");
           logger.log(buffer.clone().readString(charset));
@@ -251,6 +262,29 @@ public final class HttpLoggingInterceptor implements Interceptor {
     return response;
   }
 
+  /**
+   * Returns true if the body in question probably contains human readable text. Uses a small sample
+   * of code points to detect unicode control characters commonly used in binary file signatures.
+   */
+  static boolean isPlaintext(Buffer buffer) throws EOFException {
+    try {
+      Buffer prefix = new Buffer();
+      long byteCount = buffer.size() < 64 ? buffer.size() : 64;
+      buffer.copyTo(prefix, 0, byteCount);
+      for (int i = 0; i < 16; i++) {
+        if (prefix.exhausted()) {
+          break;
+        }
+        if (Character.isISOControl(prefix.readUtf8CodePoint())) {
+          return false;
+        }
+      }
+      return true;
+    } catch (EOFException e) {
+      return false; // Truncated UTF-8 sequence.
+    }
+  }
+
   private boolean bodyEncoded(Headers headers) {
     String contentEncoding = headers.get("Content-Encoding");
     return contentEncoding != null && !contentEncoding.equalsIgnoreCase("identity");
diff --git a/okhttp-logging-interceptor/src/test/java/okhttp3/logging/HttpLoggingInterceptorTest.java b/okhttp-logging-interceptor/src/test/java/okhttp3/logging/HttpLoggingInterceptorTest.java
index 88630b500..3159ad2f7 100644
--- a/okhttp-logging-interceptor/src/test/java/okhttp3/logging/HttpLoggingInterceptorTest.java
+++ b/okhttp-logging-interceptor/src/test/java/okhttp3/logging/HttpLoggingInterceptorTest.java
@@ -37,6 +37,7 @@ import org.junit.Rule;
 import org.junit.Test;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertSame;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
@@ -638,6 +639,60 @@ public final class HttpLoggingInterceptorTest {
         .assertNoMoreLogs();
   }
 
+  @Test public void isPlaintext() throws IOException {
+    assertTrue(HttpLoggingInterceptor.isPlaintext(new Buffer()));
+    assertTrue(HttpLoggingInterceptor.isPlaintext(new Buffer().writeUtf8("abc")));
+    assertTrue(HttpLoggingInterceptor.isPlaintext(new Buffer().writeByte(0x80)));
+    assertFalse(HttpLoggingInterceptor.isPlaintext(new Buffer().writeByte(0x00)));
+    assertFalse(HttpLoggingInterceptor.isPlaintext(new Buffer().writeByte(0xc0)));
+  }
+
+  @Test public void responseBodyIsBinary() throws IOException {
+    setLevel(Level.BODY);
+    Buffer buffer = new Buffer();
+    buffer.writeUtf8CodePoint(0x89);
+    buffer.writeUtf8CodePoint(0x50);
+    buffer.writeUtf8CodePoint(0x4e);
+    buffer.writeUtf8CodePoint(0x47);
+    buffer.writeUtf8CodePoint(0x0d);
+    buffer.writeUtf8CodePoint(0x0a);
+    buffer.writeUtf8CodePoint(0x1a);
+    buffer.writeUtf8CodePoint(0x0a);
+    server.enqueue(new MockResponse()
+        .setBody(buffer)
+        .setHeader("Content-Type", "image/png; charset=utf-8"));
+    Response response = client.newCall(request().build()).execute();
+    response.body().close();
+
+    applicationLogs
+        .assertLogEqual("--> GET " + url + " http/1.1")
+        .assertLogEqual("--> END GET")
+        .assertLogMatch("<-- 200 OK " + url + " \\(\\d+ms\\)")
+        .assertLogEqual("Content-Length: 9")
+        .assertLogEqual("Content-Type: image/png; charset=utf-8")
+        .assertLogMatch("OkHttp-Sent-Millis: \\d+")
+        .assertLogMatch("OkHttp-Received-Millis: \\d+")
+        .assertLogEqual("")
+        .assertLogEqual("<-- END HTTP (binary 9-byte body omitted)")
+        .assertNoMoreLogs();
+
+    networkLogs
+        .assertLogEqual("--> GET " + url + " http/1.1")
+        .assertLogEqual("Host: " + host)
+        .assertLogEqual("Connection: Keep-Alive")
+        .assertLogEqual("Accept-Encoding: gzip")
+        .assertLogMatch("User-Agent: okhttp/.+")
+        .assertLogEqual("--> END GET")
+        .assertLogMatch("<-- 200 OK " + url + " \\(\\d+ms\\)")
+        .assertLogEqual("Content-Length: 9")
+        .assertLogEqual("Content-Type: image/png; charset=utf-8")
+        .assertLogMatch("OkHttp-Sent-Millis: \\d+")
+        .assertLogMatch("OkHttp-Received-Millis: \\d+")
+        .assertLogEqual("")
+        .assertLogEqual("<-- END HTTP (binary 9-byte body omitted)")
+        .assertNoMoreLogs();
+  }
+
   private Request.Builder request() {
     return new Request.Builder().url(url);
   }