Dear Masood Abbasi ,

The journal does not seem to say anything about this. Most likely because in general there is no word-limit for open access journals. See for example:

-PLOS ONE: They state “Manuscripts can be any length. There are no restrictions on word count, number of figures, or amount of supporting information.” But obviously they also state “We encourage you to present and discuss your findings concisely.” (https://journals.plos.org/plosone/s/submission-guidelines )

-International Journal of Molecular Sciences: They state “IJMS has no restrictions on the maximum length of manuscripts, provided that the text is concise and comprehensive.” (https://www.mdpi.com/journal/ijms/instructions )

-Scientific Reports: They also indicate “In most cases, we do not impose strict limits on word count or page number.” But the recommend “Articles should ideally be no more than 11 typeset pages” and “The main text should be no more than 4,500 words (not including Abstract, Methods, References and figure legends)” (https://www.nature.com/srep/author-instructions/submission-guidelines )

Or the maximum is quite generous:

-Frontiers (in Communications and Networks): “Original Research articles are peer-reviewed, have a maximum word count of 12,000 and may contain no more than 15 Figures/Tables.” (https://www.frontiersin.org/journals/communications-and-networks/for-authors/article-types )

So, they impose no restrictions but as many journals say always try to be as concise and comprehensive as possible.

Best regards.