Submit 'em all. Meaning, all that are "good" and not blacklisted, spammy (you don't want those to point to your money site anyways).
But don't do it all at once. Best is to dreep feed them. Indexing services have that option. Either all at once (not recommended), over a few days or set amount of links per day.
Watch out for link velocity so you don't trigger Google and you'll be good.
As an example, if your website traffic is 0-10 visitors/day, it wouldn't look right that you get 1000 links in a day.
Gl
Thank you. The thing I don't understand is that I figure the ones that are 'hidden' in the link finding tools are probably the ones not indexed, yes? If so how do I find those? Because in Ubersuggest, for example, I can see maybe 10% of the links, and then the rest are a mystery - it just doesn't list them all (even on a paid account). If I use another tool, I can see different backlinks sometimes. So how do I find all the ones that are not showing in these tools, so I can then run them through the indexer? And this then means that I would have to manually find every single link to my site out there, in order to use the link indexing tool? That sounds extremely tedious. Why not just identify the ones that are not indexed? Or is that not possible?
You'll have to track your links, spreadsheet or something if you're building links manually or with other tools. By gathering links in a sheet, you'll know which are indexed or not.
You are somewhat correct there. It doesn't mean that they are not all indexed, it just means that those tools didn't find those backlinks yet.
Not all SEO tools work the same when tracking links. Some count some links some tools don't. Some find your link faster some don't.
If you're having trouble finding out which links are indexed, there are few things you can do. You can sign up for free account with Ahrefs, add your domain and run backlinks report. You can do that for multiple other tools as well.
Once you've gathered a list, go ahead and index them with indexification services, or free methods which there are plenty on this forum.
I'd suggest getting a Google Search Console connected to your site if you haven't already, go to Links on the bottom of the left sidebar, export all links. Those are the backlinks that google knows, crawled them and identified your site's URL on them.
Pro tip: if you have bunch of backlinks,this can help you gather more links that Google identified, via Google Search Console. You can add more domain properties to Google (ie.
WWW.yoursite.com, yoursite.com/blog etc.) and export more links. Some backlinks will not link to the exact property (some will have www. and some won't). So download all lists, and remove duplicates and voila, you got yourself some links that you didn't know were there, beacuse Google shows only links for that exact property only.