afaik no such a tool is available. Spectra must be interpreted

Do you wish to assign IR/Raman bands by using an online software? I am afraid it is possibly not a good option because even if you find one, it is very difficult to say whether the assignments would be perfectly reliable or not. The main reason for this is that a single IR/Raman band is always a combination of several normal modes/vibrations, each having different %age contributions in the integrated intensity of the band. Therefore it is always preferable to assign bands after doing Potential Energy Distribution (PED) calculations. We generally use the Gar2PED software for doing PED calculations from DFT optimized structure of the molecule and assign the IR/Raman bands with the help of PED calculations. For references to assignments using PED, you can go through some of my publications.

Thanks a lot to everyone for your helpful comments