diff --git a/crypto/base64/base64.c b/crypto/base64/base64.c
index 349452d..3d92059 100644
--- a/crypto/base64/base64.c
+++ b/crypto/base64/base64.c
@@ -265,14 +265,17 @@
   const uint8_t is_slash = constant_time_eq_8(a, '/');
   const uint8_t is_equals = constant_time_eq_8(a, '=');
 
-  uint8_t ret = 0xff;  // 0xff signals invalid.
-  ret = constant_time_select_8(is_upper, a - 'A', ret);       // [0,26)
-  ret = constant_time_select_8(is_lower, a - 'a' + 26, ret);  // [26,52)
-  ret = constant_time_select_8(is_digit, a - '0' + 52, ret);  // [52,62)
-  ret = constant_time_select_8(is_plus, 62, ret);
-  ret = constant_time_select_8(is_slash, 63, ret);
-  // Padding maps to zero, to be further handled by the caller.
-  ret = constant_time_select_8(is_equals, 0, ret);
+  uint8_t ret = 0;
+  ret |= is_upper & (a - 'A');       // [0,26)
+  ret |= is_lower & (a - 'a' + 26);  // [26,52)
+  ret |= is_digit & (a - '0' + 52);  // [52,62)
+  ret |= is_plus & 62;
+  ret |= is_slash & 63;
+  // Invalid inputs, 'A', and '=' have all been mapped to zero. Map invalid
+  // inputs to 0xff. Note '=' is padding and handled separately by the caller.
+  const uint8_t is_valid =
+      is_upper | is_lower | is_digit | is_plus | is_slash | is_equals;
+  ret |= ~is_valid;
   return ret;
 }
 
diff --git a/tool/speed.cc b/tool/speed.cc
index 613e630..b91a4ce 100644
--- a/tool/speed.cc
+++ b/tool/speed.cc
@@ -26,6 +26,7 @@
 
 #include <openssl/aead.h>
 #include <openssl/aes.h>
+#include <openssl/base64.h>
 #include <openssl/bn.h>
 #include <openssl/curve25519.h>
 #include <openssl/crypto.h>
@@ -992,6 +993,48 @@
   return true;
 }
 
+static bool SpeedBase64(const std::string &selected) {
+  if (!selected.empty() && selected.find("base64") == std::string::npos) {
+    return true;
+  }
+
+  static const char kInput[] =
+    "MIIDtTCCAp2gAwIBAgIJALW2IrlaBKUhMA0GCSqGSIb3DQEBCwUAMEUxCzAJBgNV"
+    "BAYTAkFVMRMwEQYDVQQIEwpTb21lLVN0YXRlMSEwHwYDVQQKExhJbnRlcm5ldCBX"
+    "aWRnaXRzIFB0eSBMdGQwHhcNMTYwNzA5MDQzODA5WhcNMTYwODA4MDQzODA5WjBF"
+    "MQswCQYDVQQGEwJBVTETMBEGA1UECBMKU29tZS1TdGF0ZTEhMB8GA1UEChMYSW50"
+    "ZXJuZXQgV2lkZ2l0cyBQdHkgTHRkMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIB"
+    "CgKCAQEAugvahBkSAUF1fC49vb1bvlPrcl80kop1iLpiuYoz4Qptwy57+EWssZBc"
+    "HprZ5BkWf6PeGZ7F5AX1PyJbGHZLqvMCvViP6pd4MFox/igESISEHEixoiXCzepB"
+    "rhtp5UQSjHD4D4hKtgdMgVxX+LRtwgW3mnu/vBu7rzpr/DS8io99p3lqZ1Aky+aN"
+    "lcMj6MYy8U+YFEevb/V0lRY9oqwmW7BHnXikm/vi6sjIS350U8zb/mRzYeIs2R65"
+    "LUduTL50+UMgat9ocewI2dv8aO9Dph+8NdGtg8LFYyTTHcUxJoMr1PTOgnmET19W"
+    "JH4PrFwk7ZE1QJQQ1L4iKmPeQistuQIDAQABo4GnMIGkMB0GA1UdDgQWBBT5m6Vv"
+    "zYjVYHG30iBE+j2XDhUE8jB1BgNVHSMEbjBsgBT5m6VvzYjVYHG30iBE+j2XDhUE"
+    "8qFJpEcwRTELMAkGA1UEBhMCQVUxEzARBgNVBAgTClNvbWUtU3RhdGUxITAfBgNV"
+    "BAoTGEludGVybmV0IFdpZGdpdHMgUHR5IEx0ZIIJALW2IrlaBKUhMAwGA1UdEwQF"
+    "MAMBAf8wDQYJKoZIhvcNAQELBQADggEBAD7Jg68SArYWlcoHfZAB90Pmyrt5H6D8"
+    "LRi+W2Ri1fBNxREELnezWJ2scjl4UMcsKYp4Pi950gVN+62IgrImcCNvtb5I1Cfy"
+    "/MNNur9ffas6X334D0hYVIQTePyFk3umI+2mJQrtZZyMPIKSY/sYGQHhGGX6wGK+"
+    "GO/og0PQk/Vu6D+GU2XRnDV0YZg1lsAsHd21XryK6fDmNkEMwbIWrts4xc7scRrG"
+    "HWy+iMf6/7p/Ak/SIicM4XSwmlQ8pPxAZPr+E2LoVd9pMpWUwpW2UbtO5wsGTrY5"
+    "sO45tFNN/y+jtUheB1C2ijObG/tXELaiyCdM+S/waeuv0MXtI4xnn1A=";
+
+  std::vector<uint8_t> out(strlen(kInput));
+  size_t len;
+  TimeResults results;
+  if (!TimeFunction(&results, [&]() -> bool {
+        return EVP_DecodeBase64(out.data(), &len, out.size(),
+                                reinterpret_cast<const uint8_t *>(kInput),
+                                strlen(kInput));
+      })) {
+    fprintf(stderr, "base64 decode failed.\n");
+    return false;
+  }
+  results.PrintWithBytes("base64 decode", strlen(kInput));
+  return true;
+}
+
 static TRUST_TOKEN_PRETOKEN *trust_token_pretoken_dup(
     TRUST_TOKEN_PRETOKEN *in) {
   TRUST_TOKEN_PRETOKEN *out =
@@ -1390,7 +1433,8 @@
       !SpeedTrustToken("TrustToken-Exp2PMB-Batch1",
                        TRUST_TOKEN_experiment_v2_pmb(), 1, selected) ||
       !SpeedTrustToken("TrustToken-Exp2PMB-Batch10",
-                       TRUST_TOKEN_experiment_v2_pmb(), 10, selected)) {
+                       TRUST_TOKEN_experiment_v2_pmb(), 10, selected) ||
+      !SpeedBase64(selected)) {
     return false;
   }
 #if defined(BORINGSSL_FIPS)