Q:

Bibliography with only initials of names

I have a .bib file created automatically with jabRef. When I use it in my thesis some of the author names are full and some only initial letter.
Why? How can I have only inital for all?
Here is a MWE:
    \documentclass[a4paper,11pt,titlepage,twoside,openright]{book}
    \usepackage[utf8]{inputenc}
    \usepackage[italian,english]{babel}
    \usepackage[T1]{fontenc}
    \usepackage{csquotes}
    \usepackage{hyperref}
    \usepackage[style=numeric-comp,sorting=none,sortcites=true,doi=false,url=false, hyperref]{biblatex}

    \renewbibmacro{in:}{ %eliminates the 'in' in the biblio
    \ifentrytype{article}{}{%
    \printtext{\bibstring{in}\intitlepunct}}}

    \renewcommand*{\bibfont}{\small}

    \bibliography{bib_tesi}
    \AtEveryBibitem{%
    \clearfield{month}%
    \clearlist{language}%
    }

    \begin{document}

    \backmatter
    \begingroup
    \phantomsection
    \printbibliography
    \addcontentsline{toc}{chapter}{Bibliography}      
    \endgroup

    \end{document}

A:

To achieve what you want it suffices to load biblatex package with the option giveninits=true.
So in your document put
\usepackage[%
    style=numeric-comp,sorting=none,
    sortcites=true,doi=false,url=false,
    giveninits=true,hyperref]{biblatex}

Older versions of biblatex used firstinits rather than giveninits: the previous option still works at present but is deprecated.

