diff --git a/cpp/StftPitchShift/STFT.h b/cpp/StftPitchShift/STFT.h
index 4432cdb..44afd0c 100755
--- a/cpp/StftPitchShift/STFT.h
+++ b/cpp/StftPitchShift/STFT.h
@@ -25,25 +25,26 @@ namespace stftpitchshift
 
   public:
 
-    STFT(const size_t framesize, const size_t hopsize, const bool chronometry = false) :
-      STFT(std::make_shared<RFFT>(), std::make_tuple(framesize, framesize), hopsize, chronometry)
+    STFT(const size_t framesize, const size_t hopsize, const size_t padsize, const bool chronometry = false) :
+      STFT(std::make_shared<RFFT>(), std::make_tuple(framesize, framesize), hopsize, padsize, chronometry)
     {
     }
 
-    STFT(const std::shared_ptr<FFT> fft, const size_t framesize, const size_t hopsize, const bool chronometry = false) :
-      STFT(fft, std::make_tuple(framesize, framesize), hopsize, chronometry)
+    STFT(const std::shared_ptr<FFT> fft, const size_t framesize, const size_t hopsize, const size_t padsize, const bool chronometry = false) :
+      STFT(fft, std::make_tuple(framesize, framesize), hopsize, padsize, chronometry)
     {
     }
 
-    STFT(const std::tuple<size_t, size_t> framesize, const size_t hopsize, const bool chronometry = false) :
-      STFT(std::make_shared<RFFT>(), framesize, hopsize, chronometry)
+    STFT(const std::tuple<size_t, size_t> framesize, const size_t hopsize, const size_t padsize, const bool chronometry = false) :
+      STFT(std::make_shared<RFFT>(), framesize, hopsize, padsize, chronometry)
     {
     }
 
-    STFT(const std::shared_ptr<FFT> fft, const std::tuple<size_t, size_t> framesize, const size_t hopsize, const bool chronometry = false) :
+    STFT(const std::shared_ptr<FFT> fft, const std::tuple<size_t, size_t> framesize, const size_t hopsize, const size_t padsize, const bool chronometry = false) :
       fft(fft),
       framesize(framesize),
       hopsize(hopsize),
+      padsize(padsize),
       chronometry(chronometry)
     {
       const auto analysis_window_size = std::get<0>(framesize);
@@ -74,8 +75,8 @@ namespace stftpitchshift
         [unitygain](T value) { return value * unitygain; });
 
       buffer.size = analysis_window_size;
-      buffer.time.resize(buffer.size);
-      buffer.freq.resize(buffer.size / 2 + 1);
+      buffer.time.resize(buffer.size * padsize);
+      buffer.freq.resize(buffer.size * padsize / 2 + 1);
     }
 
     void operator()(const std::span<const T> input, const std::span<T> output, const std::function<void(std::span<std::complex<T>> dft)> callback)
@@ -143,6 +144,7 @@ namespace stftpitchshift
     const std::shared_ptr<FFT> fft;
     const std::tuple<size_t, size_t> framesize;
     const size_t hopsize;
+    const size_t padsize;
     const bool chronometry;
 
     struct
diff --git a/cpp/StftPitchShift/StftPitchShift.cpp b/cpp/StftPitchShift/StftPitchShift.cpp
index 438b0e5..352ff11 100755
--- a/cpp/StftPitchShift/StftPitchShift.cpp
+++ b/cpp/StftPitchShift/StftPitchShift.cpp
@@ -12,6 +12,7 @@ StftPitchShift::StftPitchShift(
   const double samplerate,
   const size_t framesize,
   const size_t hopsize,
+  const size_t padsize,
   const bool normalization,
   const bool chronometry) :
   StftPitchShift(
@@ -19,6 +20,7 @@ StftPitchShift::StftPitchShift(
     samplerate,
     std::make_tuple(framesize, framesize),
     hopsize,
+    padsize,
     normalization,
     chronometry)
 {
@@ -28,6 +30,7 @@ StftPitchShift::StftPitchShift(
   const double samplerate,
   const std::tuple<size_t, size_t> framesize,
   const size_t hopsize,
+  const size_t padsize,
   const bool normalization,
   const bool chronometry) :
   StftPitchShift(
@@ -35,6 +38,7 @@ StftPitchShift::StftPitchShift(
     samplerate,
     framesize,
     hopsize,
+    padsize,
     normalization,
     chronometry)
 {
@@ -45,6 +49,7 @@ StftPitchShift::StftPitchShift(
   const double samplerate,
   const size_t framesize,
   const size_t hopsize,
+  const size_t padsize,
   const bool normalization,
   const bool chronometry) :
   StftPitchShift(
@@ -52,6 +57,7 @@ StftPitchShift::StftPitchShift(
     samplerate,
     std::make_tuple(framesize, framesize),
     hopsize,
+    padsize,
     normalization,
     chronometry)
 {
@@ -62,12 +68,14 @@ StftPitchShift::StftPitchShift(
   const double samplerate,
   const std::tuple<size_t, size_t> framesize,
   const size_t hopsize,
+  const size_t padsize,
   const bool normalization,
   const bool chronometry) :
   fft(fft),
   samplerate(samplerate),
   framesize(framesize),
   hopsize(hopsize),
+  padsize(padsize),
   normalization(normalization),
   chronometry(chronometry)
 {
@@ -117,14 +125,14 @@ void StftPitchShift::shiftpitch(
   // preemptively clear output #30
   std::fill(output.begin(), output.end(), float(0));
 
-  StftPitchShiftCore<float> core(fft, samplerate, framesize, hopsize);
+  StftPitchShiftCore<float> core(fft, samplerate, framesize, hopsize, padsize);
 
   core.factors(factors);
   core.quefrency(quefrency);
   core.distortion(distortion);
   core.normalization(normalization);
 
-  STFT<float> stft(fft, framesize, hopsize, chronometry);
+  STFT<float> stft(fft, framesize, hopsize, padsize, chronometry);
 
   stft(input, output, [&](std::span<std::complex<float>> dft)
   {
@@ -142,14 +150,14 @@ void StftPitchShift::shiftpitch(
   // preemptively clear output #30
   std::fill(output.begin(), output.end(), double(0));
 
-  StftPitchShiftCore<double> core(fft, samplerate, framesize, hopsize);
+  StftPitchShiftCore<double> core(fft, samplerate, framesize, hopsize, padsize);
 
   core.factors(factors);
   core.quefrency(quefrency);
   core.distortion(distortion);
   core.normalization(normalization);
 
-  STFT<double> stft(fft, framesize, hopsize, chronometry);
+  STFT<double> stft(fft, framesize, hopsize, padsize, chronometry);
 
   stft(input, output, [&](std::span<std::complex<double>> dft)
   {
diff --git a/cpp/StftPitchShift/StftPitchShift.h b/cpp/StftPitchShift/StftPitchShift.h
index be1a37f..112cdf0 100755
--- a/cpp/StftPitchShift/StftPitchShift.h
+++ b/cpp/StftPitchShift/StftPitchShift.h
@@ -21,6 +21,7 @@ namespace stftpitchshift
      * @param samplerate The sample rate of the signal in hertz.
      * @param framesize The STFT frame size in samples (analysis = synthesis).
      * @param hopsize The STFT hop size in samples.
+     * @param padsize The FFT zero padding factor.
      * @param normalization Optionally enable spectral rms normalization.
      * @param chronometry Optionally enable runtime measurements.
      */
@@ -28,6 +29,7 @@ namespace stftpitchshift
       const double samplerate,
       const size_t framesize,
       const size_t hopsize,
+      const size_t padsize = 1,
       const bool normalization = false,
       const bool chronometry = false);
 
@@ -35,6 +37,7 @@ namespace stftpitchshift
      * @param samplerate The sample rate of the signal in hertz.
      * @param framesize The STFT frame size in samples (analysis >= synthesis).
      * @param hopsize The STFT hop size in samples.
+     * @param padsize The FFT zero padding factor.
      * @param normalization Optionally enable spectral rms normalization.
      * @param chronometry Optionally enable runtime measurements.
      */
@@ -42,6 +45,7 @@ namespace stftpitchshift
       const double samplerate,
       const std::tuple<size_t, size_t> framesize,
       const size_t hopsize,
+      const size_t padsize = 1,
       const bool normalization = false,
       const bool chronometry = false);
 
@@ -50,6 +54,7 @@ namespace stftpitchshift
      * @param samplerate The sample rate of the signal in hertz.
      * @param framesize The STFT frame size in samples (analysis = synthesis).
      * @param hopsize The STFT hop size in samples.
+     * @param padsize The FFT zero padding factor.
      * @param normalization Optionally enable spectral rms normalization.
      * @param chronometry Optionally enable runtime measurements.
      */
@@ -58,6 +63,7 @@ namespace stftpitchshift
       const double samplerate,
       const size_t framesize,
       const size_t hopsize,
+      const size_t padsize = 1,
       const bool normalization = false,
       const bool chronometry = false);
 
@@ -66,6 +72,7 @@ namespace stftpitchshift
      * @param samplerate The sample rate of the signal in hertz.
      * @param framesize The STFT frame size in samples (analysis >= synthesis).
      * @param hopsize The STFT hop size in samples.
+     * @param padsize The FFT zero padding factor.
      * @param normalization Optionally enable spectral rms normalization.
      * @param chronometry Optionally enable runtime measurements.
      */
@@ -74,6 +81,7 @@ namespace stftpitchshift
       const double samplerate,
       const std::tuple<size_t, size_t> framesize,
       const size_t hopsize,
+      const size_t padsize = 1,
       const bool normalization = false,
       const bool chronometry = false);
 
@@ -139,6 +147,7 @@ namespace stftpitchshift
     const double samplerate;
     const std::tuple<size_t, size_t> framesize;
     const size_t hopsize;
+    const size_t padsize;
     const bool normalization;
     const bool chronometry;
 
diff --git a/cpp/StftPitchShift/StftPitchShiftCore.h b/cpp/StftPitchShift/StftPitchShiftCore.h
index 185bf6c..a3db9f6 100755
--- a/cpp/StftPitchShift/StftPitchShiftCore.h
+++ b/cpp/StftPitchShift/StftPitchShiftCore.h
@@ -20,24 +20,28 @@ namespace stftpitchshift
     StftPitchShiftCore(
       const double samplerate,
       const size_t framesize,
-      const size_t hopsize) :
+      const size_t hopsize,
+      const size_t padsize) :
       StftPitchShiftCore(
         std::make_shared<RFFT>(),
         samplerate,
         std::make_tuple(framesize, framesize),
-        hopsize)
+        hopsize,
+        padsize)
     {
     }
 
     StftPitchShiftCore(
       const double samplerate,
       const std::tuple<size_t, size_t> framesize,
-      const size_t hopsize) :
+      const size_t hopsize,
+      const size_t padsize) :
       StftPitchShiftCore(
         std::make_shared<RFFT>(),
         samplerate,
         framesize,
-        hopsize)
+        hopsize,
+        padsize)
     {
     }
 
@@ -45,12 +49,14 @@ namespace stftpitchshift
       const std::shared_ptr<FFT> fft,
       const double samplerate,
       const size_t framesize,
-      const size_t hopsize) :
+      const size_t hopsize,
+      const size_t padsize) :
       StftPitchShiftCore(
         fft,
         samplerate,
         std::make_tuple(framesize, framesize),
-        hopsize)
+        hopsize,
+        padsize)
     {
     }
 
@@ -58,15 +64,17 @@ namespace stftpitchshift
       const std::shared_ptr<FFT> fft,
       const double samplerate,
       const std::tuple<size_t, size_t> framesize,
-      const size_t hopsize) :
+      const size_t hopsize,
+      const size_t padsize) :
       fft(fft),
       samplerate(samplerate),
       framesize(framesize),
       hopsize(hopsize),
-      vocoder(samplerate, framesize, hopsize),
-      pitcher(samplerate, std::get<0>(framesize)),
-      cepster(fft, samplerate, std::get<0>(framesize)),
-      envelope(std::get<0>(framesize) / 2 + 1)
+      padsize(padsize),
+      vocoder(samplerate, framesize, hopsize, padsize),
+      pitcher(samplerate, std::get<0>(framesize) * padsize),
+      cepster(fft, samplerate, std::get<0>(framesize) * padsize),
+      envelope(std::get<0>(framesize) * padsize / 2 + 1)
     {
     }
 
@@ -175,6 +183,7 @@ namespace stftpitchshift
     const double samplerate;
     const std::tuple<size_t, size_t> framesize;
     const size_t hopsize;
+    const size_t padsize;
 
     Vocoder<T> vocoder;
     Pitcher<T> pitcher;
diff --git a/cpp/StftPitchShift/Vocoder.h b/cpp/StftPitchShift/Vocoder.h
index 37f73bf..748bcec 100755
--- a/cpp/StftPitchShift/Vocoder.h
+++ b/cpp/StftPitchShift/Vocoder.h
@@ -17,19 +17,19 @@ namespace stftpitchshift
 
   public:
 
-    Vocoder(const double samplerate, const size_t framesize, const size_t hopsize) :
-      Vocoder(samplerate, std::make_tuple(framesize, framesize), hopsize)
+    Vocoder(const double samplerate, const size_t framesize, const size_t hopsize, const size_t padsize) :
+      Vocoder(samplerate, std::make_tuple(framesize, framesize), hopsize, padsize)
     {
     }
 
-    Vocoder(const double samplerate, const std::tuple<size_t, size_t> framesize, const size_t hopsize)
+    Vocoder(const double samplerate, const std::tuple<size_t, size_t> framesize, const size_t hopsize, const size_t padsize)
     {
       const double pi = 2.0 * std::acos(-1.0);
 
-      const size_t dftsize = std::get<0>(framesize) / 2 + 1;
+      const size_t dftsize = std::get<0>(framesize) * padsize / 2 + 1;
 
-      stft_freq_inc = samplerate / std::get<0>(framesize);
-      stft_phase_inc = pi * hopsize / std::get<0>(framesize);
+      stft_freq_inc = samplerate / (std::get<0>(framesize) * padsize);
+      stft_phase_inc = pi * hopsize / (std::get<0>(framesize) * padsize);
 
       encode_phase_buffer.resize(dftsize);
       decode_phase_buffer.resize(dftsize);
diff --git a/cpp/StftPitchShift/main.cpp b/cpp/StftPitchShift/main.cpp
index 6f728c8..c752cbf 100755
--- a/cpp/StftPitchShift/main.cpp
+++ b/cpp/StftPitchShift/main.cpp
@@ -67,6 +67,7 @@ int main(int argc, char** argv)
         samplerate,
         cli.framesize,
         std::get<1>(cli.framesize) / cli.hoprate,
+        1, // TODO
         cli.normalization,
         cli.chronometry);
 
diff --git a/examples/realtime.cpp b/examples/realtime.cpp
index 42aaa9e..614c1ea 100644
--- a/examples/realtime.cpp
+++ b/examples/realtime.cpp
@@ -13,9 +13,11 @@ using namespace stftpitchshift;
 
 // basic parameters
 // - samplerate as required
-// - overlap at least 4
+// - STFT overlap factor at least 4
+// - FFT zero padding factor at least 1
 const double samplerate = 44100;
 const size_t overlap = 4;
+const size_t padding = 1;
 
 // analysis and synthesis window sizes
 // power of two each of them
@@ -48,8 +50,8 @@ int main()
   buffer.input.resize(total_buffer_size);
   buffer.output.resize(total_buffer_size);
 
-  stft = std::make_shared<STFT<double>>(framesize, hopsize);
-  core = std::make_shared<StftPitchShiftCore<double>>(samplerate, framesize, hopsize);
+  stft = std::make_shared<STFT<double>>(framesize, hopsize, padding);
+  core = std::make_shared<StftPitchShiftCore<double>>(samplerate, framesize, hopsize, padding);
 
   // set pitch shifting parameters as required