--- a/dom/media/MediaDecoder.cpp
+++ b/dom/media/MediaDecoder.cpp
@@ -1025,16 +1025,25 @@ bool
 MediaDecoder::ShouldThrottleDownload()
 {
   // We throttle the download if either the throttle override pref is set
   // (so that we can always throttle in Firefox on mobile) or if the download
   // is fast enough that there's no concern about playback being interrupted.
   MOZ_ASSERT(NS_IsMainThread());
   NS_ENSURE_TRUE(mDecoderStateMachine, false);
 
+  int64_t length = mResource->GetLength();
+  if (length > 0 &&
+      length <= int64_t(MediaPrefs::MediaMemoryCacheMaxSize()) * 1024) {
+    // Don't throttle the download of small resources. This is to speed
+    // up seeking, as seeks into unbuffered ranges would require starting
+    // up a new HTTP transaction, which adds latency.
+    return false;
+  }
+
   if (Preferences::GetBool("media.throttle-regardless-of-download-rate",
                            false)) {
     return true;
   }
 
   MediaStatistics stats = GetStatistics();
   if (!stats.mDownloadRateReliable || !stats.mPlaybackRateReliable) {
     return false;