MolDraw › Chemistry tools › NMR Viewer
Free NMR Viewer
Open a 1H or 13C NMR spectrum, zoom in, pick peaks, integrate and reference it. Then find solvent and grease peaks and hide them for a clean figure. Your file stays on your device.
or drop it here. JCAMP-DX (.jdx, .dx), CSV or TXT (ppm, intensity), or Bruker (zip of the folder, or the 1r and procs files together).
Examples are simulated spectra with real solvent and impurity shifts, so Find impurities shows hits right away. Download the sample .jdx.
Find impurities
Peaks
Integrals
Reference (shift calibration)
How to use the NMR viewer
- Open your file, or press an example button to try it.
- Drag across the plot to zoom. Choose Pan to slide left and right. Double-click to see the whole spectrum.
- Peaks are picked for you. Move the Threshold slider for more or fewer. Choose Pick peak to add one by clicking.
- Choose Integrate and drag across a peak. Set "First integral =" to the number of H it stands for.
- Press Reference to solvent so the solvent peak sits at its true value.
- Pick your solvent and press Find impurities. Tick or untick a result to show its marks. Press Remove to hide its peaks.
- Export a PNG for your report, or CSV and JCAMP-DX for other programs.
About the impurity table
Shifts for 1H and 13C come from Fulmer, Miller, Sherden, Gottlieb, Nudelman, Stoltz, Bercaw and Goldberg, "NMR Chemical Shifts of Trace Impurities: Common Laboratory Solvents, Organics, and Gases in Deuterated Solvents Relevant to the Organometallic Chemist", Organometallics 2010, 29, 2176-2179 (doi:10.1021/om100106e). It extends Gottlieb, Kotlyar and Nudelman, J. Org. Chem. 1997, 62, 7512. The table covers about 45 common solvents, reagents, greases and gases in 12 deuterated solvents.
Removing an impurity is a display edit. It draws a straight line across that compound's peaks. Do not use a cleaned spectrum as raw data in a paper or thesis. Report the impurities instead.
Frequently asked questions
Is my spectrum uploaded to a server?
No. The file is read and plotted inside your browser. Nothing is sent to MolDraw or anyone else.
Which file types can I open?
JCAMP-DX (.jdx, .dx) including compressed (ASDF) data, two-column CSV or TXT files with ppm and intensity, and Bruker processed data: a zip of the experiment folder, or the 1r and procs files picked together.
How does Find impurities work?
Pick the deuterated solvent. The tool looks at your peaks and lists common lab solvents and reagents whose known shifts sit within your tolerance, using the published tables of Fulmer et al. (Organometallics 2010).
What does Remove do?
It draws a straight baseline across the peaks of that impurity, only for display and export. Your file is not changed. The plot is marked Edited for display, and Undo or Restore all brings the peaks back.
Why does the MHz setting matter?
Peaks are in ppm, but coupling constants are in Hz. On a 60 MHz magnet a 7 Hz triplet is about 0.23 ppm wide. On 600 MHz it is about 0.023 ppm wide. The MHz value also sets the Hz readout.
How do I reference my spectrum?
Press Reference to solvent to put the residual solvent peak at its listed value (7.26 ppm for CDCl3), press TMS = 0 ppm, or click Reference, click a peak and type its true ppm.