The use of WL or 365 nm light lead to small size NPs using NaOH with 7.4 ± 2.4 and 7.2 ± 2.8 nm, respectively. Adding N2 to WL and 365 nm light conditions leads to 7.7 ± 2.2 nm and 5.9 ± 2.5 nm Au NPs. Therefore, upon scaling the use of 365 nm light did not significantly improve the size of the Au NPs towards smaller sizes and more monodispersed samples. The use of N2 did not bring any significant advantage under WL light conditions but significantly improved the size control towards smaller sizes when a 365 nm light was used. Similar small size NPs are obtained using LiOH under WL and 365 nm light conditions, 7.8 ± 3.2 nm and 7.5 ± 2.8 nm, respectively. Adding N2 leads to 8.1 ± 3.1 nm and 8.9 ± 2.9 nm Au NPs, respectively. In this case, the use of lower wavelengths and/or N2 did not lead to any improvement. The results therefore show the promising scalability of the synthesis presented with or without N2, although further reactor design could significantly improve the results as detailed in section S12. It is important to note that the values retrieved for the scaled-up experiments are within the uncertainties of the values retrieved from the 3 mL experiments. This confirms the promising scalability of the results obtained from the parametric screening. Last, the stability of the scaled-up experiment was investigated and the dispersion are stable for at least a year when stored in a fridge without major changes on the UV-vis features, see Figure . This result confirms the long-term stability of the surfactant-free colloidal Au NPs although a low viscosity aqueous solvent was used. A final note on the scalability is that we are not aware of experiments using polyols being scaled up, probably due to the challenges related to the viscosity of the solvent. It is also worth pointing out that that the use of polyols will typically require post-processing including washing steps in acids that are alleviated in the case of ethanol-mediated synthesis. Thus the ethanol-mediated synthesis bear promising feature to develop greener syntheses.