What is an Autoencoder?

Updated May 5, 2026

Short answer

An autoencoder is a neural network used to learn compressed representations of data and reconstruct the input.

Deep explanation

An autoencoder consists of two parts: an encoder that compresses input data into a lower-dimensional latent space, and a decoder that reconstructs the original input from that representation. It is trained using reconstruction loss (like MSE) to minimize the difference between input and output.

Real-world example

Used in image compression and noise reduction systems.

Common mistakes

  • Confusing autoencoders with supervised models, ignoring reconstruction loss, using too small latent space.

Follow-up questions

  • Is autoencoder supervised or unsupervised?
  • What loss is used?

More Autoencoders interview questions

View all →