Born in Alsace, Jacques Gruber settled in Nancy like many artists from the annexed territories. He studied in Nancy and then, from 1889, trained in Paris at the École des Arts Décoratifs and the École des Beaux-Arts where he frequented the studio of the painter Gustave Moreau.

In 1893, he returned to Nancy and joined the Daum factory as an artist-decorator, where he worked until 1897, creating models for vases, in particular one-off pieces intended for exhibitions, which show a real harmony between the decorative composition and the techniques used. At the same time, he became interested in  pyrography on wood and then on leather, with the help of René Wiener in particular. He supplied Majorelle with several furniture designs that were presented at the Nancy decorative art exhibition in 1894 (Fantaisies rabelaisiennes pyrographed table top, La Source table.) At the same time, he taught decorative composition at the Nancy School of Fine Arts until 1913.

Around 1896-1898, Jacques Gruber turned his attention to stained glass, which under Laurent-Charles Maréchal from Metz was experiencing a veritable revival in Lorraine. This interest was closely linked to the development of Art nouveau architecture in Nancy, which gave a predominant place to stained glass windows as a transitional space between the interior and exterior of buildings. It was in this field that his talent as a composer and draughtsman came to the fore and made his reputation. Louis Majorelle, Eugène Corbin and Albert Bergeret in particular commissioned him with to create stained glass windows in their private homes or factories. Jacques Gruber created the glass programme for the Chamber of Commerce and Industry, the BrasserieExcelsior, the Crédit Lyonnais, and the Magasins Réunis in Nancy. In Paris, he designed the dome of the Galeries Lafayette store in 1911, for which Majorelle produced the ironwork. His work, dominated by the naturalist repertoire, is of great graphic and sometimes pictorial quality,  and demonstrates a real mastery of the glassmaking techniques of the time.

Although he was mainly interested in this technique, Jacques Gruber did not neglect other aspects of the decorative arts. He collaborated with several industrialists and craftsmen in Nancy, supplying them with models and designs for furniture, bookbinding, and objects in flamed stoneware. He also designed menus and programmes for Nancy printers. He designed wooden objects, furniture and furniture sets, such as the imposing desk of Charles Masson, director of Magasins Réunis and Eugène Corbin’s brother-in-law (Musée de l'École de Nancy).

A member of the Ecole de Nancy's steering committee from the association's creation in 1901, Jacques Gruber took part in the movement’s main artistic events. He moved to Paris in 1914 and enjoyed a prosperous period of artistic renewal during the Art Deco period.