diff --git a/algo/core/fasta.cpp b/algo/core/fasta.cpp
index b4e0b439012daa2c6696bc76f49ba41a9b42bac0..d81fdea5f173ae214cf26bf4c9575532988d0866 100644
--- a/algo/core/fasta.cpp
+++ b/algo/core/fasta.cpp
@@ -269,3 +269,18 @@ ostream &operator<<(ostream &out, const Sequence &seq) {
   }
   return out;
 }
+
+int nb_sequences_in_fasta(string f)
+{
+  OnlineFasta *sequences = new OnlineFasta(f, 1, " ");
+  int nb_sequences = 0 ;
+
+  while (sequences->hasNext())
+    {
+      sequences->next();
+      nb_sequences++ ;
+    }
+
+  cout << "  ==> " << nb_sequences << " sequences" << endl;
+  return nb_sequences ;
+}
diff --git a/algo/core/fasta.h b/algo/core/fasta.h
index 34d6a607c440d2dac26b61f85dd97cb094a2cb29..5eda877bd98a4a69f2c62d9b0bbea17da6cd8f93 100644
--- a/algo/core/fasta.h
+++ b/algo/core/fasta.h
@@ -160,4 +160,10 @@ istream& operator>>(istream& in, Fasta& fasta);
 ostream& operator<<(ostream& out, Fasta& fasta);
 ostream &operator<<(ostream &out, const Sequence &seq);
 
+/**
+ * Count the number of sequences in a Fasta file
+ * @return the number of sequences
+ */
+int nb_sequences_in_fasta(string f);
+
 #endif