found these with a simple search...
rankwatch.com/free-tools/google-index-checker (25 max URLs at once)
zenserp.com/google-index-checker-tool (20 max URLs at once)
bulkseotools.com/bulk-google-index-checker.php (500 max URLs at once)
linkody.com/en/seo-tools/google-index-checker (10 max URLs at once)
indexchecking.com (25 max URLs at once)
These are not bad for a once-off check (and if you don't have 1000s of links to check each day), but if you're operating on a large scale I recommend you buy Scrapebox. It's only $67 with the BHW offer and they have a free addon that can check the index for unlimited URLs. Of course, you're gonna need private proxies for that (and in general for most operations that SB does), but it's all worth it if you're doing a lot of scraping (URLs, keywords, content, it doesn't matter), checking, filtering, trimming, removing duplicates, checking d0follow / nofollow, checking live baclinks... basically anything that has to do with harvesting, checking, cleaning and sorting stuff SB is the go-to tool (and no, I'm not affiliated with them in any way, I simply feel like it doesn't get the love that it needs)