Leibniz Legible

Leibniz Legible, live at leibnizlegible.com since 21 September 2026, is an access layer for the 236,795 page records of the Leibniz Nachlass that the Gottfried Wilhelm Leibniz Bibliothek in Hannover has digitized and placed online. 99.75 per cent of the pages are machine-read by a handwritten-text recognition model trained for Leibniz's hand, and every line carries its own confidence score and its provenance: which model read it, in which run, on which image. The result is searchable with tolerance for early-modern spelling and browsable in an open IIIF viewer that serves the library's public-domain scans from the project's own mirror, every page linking back to its original at the GWLB, and shows the machine reading beside them, with honest labels on every line.

The project's register is deliberately modest. Its output is machine text with about an eight percent character error rate on Latin and French, with German in Kurrent still unmeasured; it is not an edition, and it is explicitly subordinate to the Akademie-Ausgabe, which since 1923 has printed about half of the roughly 130 volumes it plans, with completion expected around 2055; one of its editors estimates that three quarters of Leibniz's papers have never been published anywhere. The point is to make all of it legible and findable while the edition continues. Ground truth for improving the model is minted by aligning the reading text of copyright-expired edition volumes onto the machine transcriptions, at scale and with the alignment confidence kept on every line.

The code is open (Apache-2.0, on GitHub), the reports are published on Zenodo (CC BY 4.0) and mirrored in the Research section here, and the datasets and model follow with their own DOIs as the phases complete. The project is built on the PHILIUMM project's open model and ground truth (ERC, Paris), whose numbers it reproduced before building on them.