SciFinder
Contains >1.3 million experimental spectra (13C-NMR, H-NMR, MS, IR) for >9000K compounds, and >24 million predicted H-NMR spectra.
Reaxys (CSUF - does not subscribe)
ChemSpider
A free chemical structure database providing access to >50 million structures.
Spectral Database System (SDBS)
Spectra for >34,000 organic compounds - electron impact Mass spectrum (EI-MS), Fourier transform infrared spectrum (FT-IR), 1H nuclear magnetic resonance (NMR) spectrum, 13C NMR spectrum, laser Raman spectrum, and electron spin resonance (ESR) spectrum.
NIST Chemistry WebBook
Provides access >16,000 compounds IR spectra, >15,000 Mass spectra , >1600 UV/Vis spectra, >27,000 Gas chromatography data, > 5000 Electronic and vibrational spectra. Other physical data such as Thermochemical data for >7000 organic and small inorganic compounds.
ChemExper
Contains >200,000 different chemicals, >10,000 MSDS, >10,000 IR spectra.
NMRShiftDB
A NMR database (web database) for organic structures and their NMR spectra. Also allows for spectrum prediction (13C, 1H, 15N and 31P NMR) as well as for searching spectra, structures and properties
Sigma-Aldrich
Find a substance using either the Data Specific Search or the Structure Search. Click on the substance number, then the Safety & Documentation tab; PDF spectra are linked on the left column, under the Certificate of Origin search.