Nidecker spent most of his career as a librarian at the Basel University Library, where he developed a cataloguing system, and was responsible for the departments of English philology and philosophy.

[1] At the 1928 Ido conference in Zürich, he spoke against the conservative arguments of Albert Nötzli; he later gave up the presidency of the Swiss federation and joined the Interlingue (then Occidental) movement.

[9] Nidecker's doctoral thesis looked at Samuel Taylor Coleridge's Theory of Life, and its usage of material by Friedrich Wilhelm Joseph Schelling.

It was never published, although Nidecker wrote a series of articles in the Révue de litterature comparée (English: Journal of Comparative Literature) on parts of the thesis, particularly on Coleridge's marginal notes concerning the works of other German philosophers.

[11] Nidecker was the author of several books and pamphlets concerning universal languages, a free economy, and music;[4] he contributed to journals about English philology and interlinguistics.