How to change .htm to .html on many files
Add a Wildcard rule from *.htm to *.html in FTP by Zaweba's bulk rename to change every extension on the server at once, with a preview first.
Changing .htm to .html across a site takes one rule in FTP by Zaweba. Tag the files in Disk, open bulk rename, add a Wildcard rule from *.htm to *.html, check the preview and press Rename. Every .htm page on the server gets its new extension in one batch.
Older sites, and sites made with older tools, often use .htm. There is nothing wrong with it, but mixing the two on one site is untidy and makes links easy to get wrong. Switching to one extension is a common job when a site is being brought up to date.
Picking the files
Open Disk from the toolbar or the Site menu and let it scan. Use Tag by with a filespec of *.htm to tag every matching file. You can look in the list, in the current branch or across the whole scan, so it is easy to limit the change to one folder if you want to try it there first.
Writing the rule
Open bulk rename and add a Wildcard rule. Put *.htm in the from side and *.html in the to side. The star stands for the rest of the name, so about.htm becomes about.html and prices.htm becomes prices.html.
The preview lists each current name beside its new one. Check that nothing unexpected is caught; a wildcard on the extension is a precise rule, but it is worth a glance before you go. Protected items are left out automatically. When you are happy, press Rename.
If you also want to tidy the names while you are at it, add more rules. Rules apply top to bottom, so a Clean up rule after the Wildcard can remove spaces and accents from the same files in the same batch.
The part that matters: links
Renaming the files is the easy half. Every link that pointed to about.htm is now broken. FTP by Zaweba's link awareness deals with this. After the rename, a window lists references to the old paths in the linked local site, looking in .php, .html, .css, .js and .htaccess files. Tick the ones to fix and Update references locally rewrites them in the same style they were written: relative links stay relative, links from the root stay rooted, full addresses stay full, and query strings and fragments are kept. Only the local files are changed, and the update can be undone.
Then upload the changed pages. Put Newer to Server is a good way to send exactly the files that changed, after showing you the list.
Old addresses out in the world
Links inside your own site are fixed by link awareness, but other sites, search engines and people's bookmarks still know the old .htm addresses. Many sites handle this with a redirect rule in .htaccess that sends visitors from the old extension to the new one. FTP by Zaweba can open and edit .htaccess with its own syntax colours, so the rule can be added in the same session. Disk treats .htaccess as protected, which means bulk rename will never rename or move it by accident.
If you are not sure how to write the redirect, your host's help pages usually have an example for their servers.
If it goes wrong
The operations log records the rename as one batch, and Undo this batch changes every name back. Link awareness changes can be undone too. Between the two, trying this on a real site is less frightening than it sounds.
Doing it without bulk rename
You could download the site, rename the files on your PC, fix the links and upload again, then delete the old .htm files from the server. It works, but there are more steps to forget. Doing it in place in FTP by Zaweba keeps the rename, the link fixes and the undo in one place.
