  We study the proposal by Kharzeev-Levin to determine entanglement entropy in
Deep Inelastic Scattering (DIS) from parton distribution functions (PDFs) and
to relate the former to the entropy of final state hadrons. We find several
uncertainties in the current comparison to data, in particular the overall
normalization, the relation between charged versus total hadron multiplicity in
the comparison to experimental results as well as different methods to
determine the number of partons in Deep Inelastic Scattering. We further
provide a comparison to data based on leading order HERA PDF as well as PDFs
obtained from an unintegrated gluon distribution subject to next-to-leading
order Balitsky-Fadin-Kuraev-Lipatov and Balitsky-Kovchegov evolution. Within
uncertainties we find good agreement with H1 data. We provide also predictions
for entropy at lower photon virtualities, where non-linear QCD dynamics is
expected to become relevant.
