What evaluation metric are used for sequence-to-sequence prediction problems? I am solving many sequence-to-sequence prediction problems using RNN/LSTM. 

What type of evaluation metrics can be used for sequence prediction problems?

One metric is the mean squared error (MSE) that we can give as a parameter during the training model. Currently, the accuracy of my sequence-to-sequence problems is very low. 

What are other ways through which we can compare the performance of our models?
I would recommend taking a look at Bilingual Evaluation Understudy(BELU) score which is commonly used in evaluating machine translation results by sequence to sequence model. Here is the reference https://en.wikipedia.org/wiki/BLEU