FamilySearch.org provides a table of NEHGR links. Links include surname and place indexes and full volumes from vol 1 published 1847 to vol 169 published 2015. Volumes through 76 published in 1922 are free on Google books and/or Internet Archive. Free. Links to American Ancestors paid volumes 1-169 are also provided.

Check out this most helpful page here:
https://familysearch.org/wiki/en/New_England_Historical_Genealogical_Register_Online

So I’m in the process of moving all the Ancestry.com paid NEHGR sources to the Archive.org free NEHGR sources. It’s a burden pay for these sources on Ancestry when they are provided free elsewhere. And a boon to the Archive.org sources is that they can be opened as PDFs or ‘full text’ formats so copying and pasting requires no effort and involves none of the odd formatting issues of Ancestry.com. Free and Easy.

I appreciate the link formats on FamilySearch.org and Archive.org. They’re short and descriptive.