Seven manuscripts of the Prose Edda have survived: six compositions of the Middle Ages and another dating to the 1600s. No one manuscript is complete, and each has variations. In addition to three fragments, the four main manuscripts are Codex Upsaliensis, Codex Wormianus, Codex Trajectinus and above all, the Codex Regius.
Codex Upsaliensis (DG 11), was composed in the first quarter of the fourteenth century and is the oldest manuscript preserved of the Edda of Snorri. It has the advantage of providing some variants that are not found in any of the three other major manuscripts (the name Gylfaginning, title of the first part of the Edda is only provided by this single text). It is preserved in the library of the University of Uppsala (Sweden).
The Codex Regius (GKS 2367 4°) was written in the first half of the fourteenth century. It is the most comprehensive of the four manuscripts, and seems closer to the original. This is why it is the basis for editions and translations of the Edda. Its name is derived from its conservation in the Royal Library of Denmark for several centuries. From 1973 to 1997, hundreds of ancient Icelandic manuscripts were returned from Denmark to Iceland, including, in 1985, the Codex Regius, which is now preserved by the Árni Magnússon Institute for Icelandic Studies in Reykjavík.
Codex Wormianus (AM 242 fol) was written in the mid-fourteenth century. It is still part of the Arnamagnæan Manuscript Collection, originally created by Árni Magnússon, in Copenhagen.
Codex Trajectinus (MSS 1374) was written around 1600. It is a copy of a manuscript that was made in the second half of the thirteenth century. It is preserved in the library of the University of Utrecht (Netherlands).