The Codex Gigas was all written by one scribe in a late version of a script known as carolingian minuscule. (This is easy to read as the script is very like the letters we use today in books, magazines and newspapers.) The letters are between 3 and 2.5 millimetres tall and these are very small for such a big book. However, by writing small and having many lines on a page, the scribe could fit all the texts he wrote onto a manageable number of leaves.

It is very difficult to estimate how long it took the scribe to write the manuscript. The scribe could have written one column in the Codex Gigas, 106 lines, in a day. If the scribe worked for six hours a day and wrote six days a week this means that the manuscript could have taken about five years to complete. If the scribe was a monk he may only have been able to work for about three hours a day, and this means that the manuscript could have taken ten years to write. As the scribe may also have ruled the lines to guide the writing before he began to write (it probably took several hours to rule one leaf), this extends the period it took to complete the manuscript. The scribe also decorated the manuscript, so this all means that the manuscript probably took at least twenty years to finish, and could even have taken thirty.

More about script in Codex Gigas