Public Lab Wiki documentation

Spectral Workbench

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For the last twelve years, Public Lab has hosted so that people everywhere can calibrate and analyze their spectra. Unfortunately, current circumstances have led us to scale back and take certain services offline. will go offline as of August 15, 2022.

The SpectralWorkbench platform runs on a combination of volunteer and paid labor by the many people that build, maintain, and operate it via Public Lab. This is an effective combination thanks to the culture of Public Lab's Coding Community. Public Lab's web ecosystem, including,,, and associated projects, takes 20 hours a week from three Code Coordinators and our sysadmin. While cost effective, it is not free. Web hosting and server costs for SpectralWorkbench are approximately $1000 per month.

We are doing our best to sustain programming and support for our community, and we need your help. Thank you for being part of our community. We can't wait to be back online with you.

Support Public Lab by making a donation today.

What is Spectral Workbench? is a web based application to collect, archive, share, and analyze spectral data, for Public Lab DIY spectrometers and other spectrometers.

With it, you can:

  • connect your USB Desktop Spectrometry Kit
  • scan and save samples
  • wavelength calibrate your spectrometer
  • plot light intensity as a function of wavelength (average digital consumer cameras have a range of 400 to 700 nm)
  • create sets of multiple spectra to visually compare and analyze scans
  • download CSV data for offline analysis
  • view others' data and discuss
  • find similar data in a database of over 60k spectra

No download is required -- just a web connection. The Chrome browser works best, but most standard-compliant browsers are supported. It is possible to use from an Android smartphone, preferably with the Firefox browser which allows you to specify which camera to look through.


Intro video


Spectral Workbench should work on Chrome (in Windows/Mac/Linux/Android, but not iOS), Firefox (Windows/Mac/Linux/Android), or Opera (Android). It may work on other browsers and we are working on expanding coverage; read more on this page:


Do you code? The codebase of Spectral Workbench is available at The server is written in Ruby on Rails, with a lot of client side code in JavaScript. You can read about the JavaScript API here.

We really need more developers, so if you are interested, please get involved! A great place to start is the "plots-dev" mailing list for software developers:


We're collecting and working our way through a range of questions about Spectral Workbench -- if you can contribute your own questions, or answer others', please do!

Title Author Updated Likes Comments
CSV import to excel @greenalastair 2 months ago 1
How do I change the reference calibration to a new current calibration? @miramarchem1 7 months ago 0
Always blank, black spectrum @Detector 11 months ago 1
how to delete unwanted spectra? @a_sivolap978 about 1 year ago 1
I need to turn on the rear camera @at-63 over 1 year ago 3
livestream cam @agraefenstein over 1 year ago 0
a quoi correspondent l'intensité en axe y et le chiffres en axe x sur le spectre? @ra_owoussi over 1 year ago 1
how to upload pictures from own cell phone @dianapicazo2104 over 1 year ago 1
how does one load a calibration file? @stef over 1 year ago 0
SW-V1 down samples the input to 256 samples irrespective of the native camera pixels available has this been fixed in V2? @stef almost 2 years ago 1
Using Thunderoptics spectrophotometer @jeffkrol about 2 years ago 4
I recently built and attached the paper spectrometer to my android smartphone. when I connect to the spectral workbench software and hit the camera icon, permission to my camera is requested. However, after I grant permission, no image appears in the spec @Ldei about 2 years ago 5
What light sources might I use to calibrate my spectrometer if I don’t have a CFL available? @mimiss over 2 years ago 8
Problem whit workbench spectra. Unable to manipulate(work) whit any image @damian_orovitz over 2 years ago 1
copying calibration issue @kog62290 almost 3 years ago 0
Spectral Workbench so slow on raspberry pi zero @danieisnietgek almost 3 years ago 3
How do I select the back camera of the smartphone? @renatoianhez about 3 years ago 2
Sorry for asking such a elementary question, what does the intensity % means? Can it shows how strong the light source is? Is it in terms of lux? @willieong about 3 years ago 1
Can you calibrate this? @jela0194 over 3 years ago 0
Is copy calibration on Spectral Workbench working? @microfibers over 3 years ago 1
How do I get the webcam feed on Spectral Workbench? @KenSuke over 3 years ago 1
How do I search for the spectra recorded by a specific user? @nnn16 over 3 years ago 4
Can detect the camara,but can't show image @JHYeh almost 4 years ago 1
Spectral Workbench 1.0 seems much more stable than 2.0 and works well for the basic analysis I am trying to do, can I get access to 1.0 without being pushed to 2.0? @B-winters almost 4 years ago 1


If you feel you've encountered a bug with the software -- very possible! Please look through existing issues listed here, file a new one if you don't see something similar, and help to add any observations to existing issues shown here.

Thanks for helping improve this open source software!

Title Author Updated Likes Comments
Nothing yet on the topic "spectral-workbench-issues" -- be the first to post something!