welcome to WebmasterWorld [webmasterworld.com], mariya!

how many legacy urls are involved?

[edited by: phranque at 8:12 am (utc) on Jun 1, 2020]

Yes, Our html pages are ranked well in google, So I need to redirect to new wordpress urls,

I've edited the typo in my post to clarify the question.
i.e., "how many...?"

6 pages are ranked well ( Main pages)

also, 2 old URLs need to redirect the same new page
3 old URLs need to redirect the same new page

Total old page count is = 82

i would do one-to-one redirects to the equivalent wordpress content.
the easiest way in your case is using a wordpress plugin.
if 82 redirects seems like a lot of work, look for a plugin that allows bulk imports.

Okay,Thanks for the reply. If you know can you suggest a good redirection plugin.

Also if do this option, if any problems are occurred just curious to know this?
.htaccess domain level 301 redirection with plugin redirect for important 4 or 5 HTML pages to WordPress pages.

I am sorry but it is not clear whether this move is all on the same domain or if the WordPress installation is on a different domain but that can make a difference in the ideal way to handle the changes.

If by

.htaccess domain level 301 redirection

you mean redirecting all of the old URL requests to the new WP domain's homepage, then no, do not do that. You should never 301 all pages to one URL. A 301 rewrite should be designed to land all requests for the old page to the new equivalent page without multiple redirects.

If you are handling the migration with .htaccess, you might want to try looking through the Apache Forum [webmasterworld.com] here for pointers or start a discussion there. ;)

not2easy,
Thanks for the reply
We are using the same domain, and redirecting all of the old URL requests to the new WP domain's matched urls.

Thank you for the extra information. It is easier when they are all in one place.

82 URLs total? That’s nothing for htaccess purposes. Also consider that any redirect done internally within WP is going to eat up vastly more server resources than even 82 separate lines in htaccess. Just remember that everything has to go before the WP section of your htaccess.

Make sure you also have an HTTP-to-HTTPS redirect for URLs that are otherwise correct. Some legitimate robots insist on requesting HTTP first, even for URLs that were not created until after the site went HTTPS. And some humans may well type-in the wrong form.