What is a textual variant?
A textual variant is any place among the manuscripts in which there is some discrepancy as to wording, spelling, or word order. Now, if 1000 manuscripts say “Jesus Christ” in one place and another 1000 say “Christ Jesus” in the same place in the text, that counts as one variant. And if only one late, unimportant manuscript differs from all the rest of the manuscripts in the wording, spelling, or word order, that too counts as a textual variant.
How many variants are there?
We’re not exactly sure because they haven’t all been counted yet. For example, a manuscript owned by the Center for the Study of New Testament Manuscripts—a MS that was unknown to biblical scholars until just a few weeks ago—has at least 29 variants that have not been found in any other manuscripts. Although it might be too much to say that every time a manuscript is discovered, new variants come to light, this is frequently the case.
Nevertheless, the best guess is that there are as many as 400,000 textual variants among our extant manuscripts.