Standard reduction potentials ${\mathrm{E}}_{{\mathrm{F}}_2/{\mathrm{F}}^{-}}^0=2.85\mathrm{V} ;{\mathrm{E}}_{{\mathrm{Cl}}_2/{\mathrm{Cl}}^{-}}^0=1.36\mathrm{V};{\mathrm{E}}_{{\mathrm{Br}}_2/{\mathrm{Br}}^{-}}^0=1.06\mathrm{V};{\mathrm{E}}_{{\mathrm{I}}_2/{\mathrm{I}}^{-}}^0=0.53\mathrm{V}$.Strongest and weakest reducing agents are respectively

For non metal electrodes 

electrode with higher SRP value left hand species readily undergoes reduction and is strong oxidizing agent,  right hand species is weak reducing agent. 

electrode with lesser SRP value right hand species readily undergoes oxidation and is strong reducing agent, left hand species is weak oxidising agent