I work on OnePassApps, so this is our own product and every line below was read off the live File Studio today, in the browser, on the panel itself.

The File Studio has two hash tabs next to each other. One of them will give you a SHA-512 checksum. The other one will not give you a SHA-512 anything, and it will not tell you that either - it just names one algorithm and moves on.

The two tabs, read off the live panel

Both live under app.onepassapps.com/studios/files. I opened each tab and read the copy.

File hash reads:

01 Source 02 Algorithm SHA-256 SHA-512 SHA-256 is the common choice for published checksums. 03 Result The checksum appears on the stage, ready to copy and compare. Nothing leaves this tab. Calculate SHA-256 One file of any type, up to 2 GiB · read on this device

Find duplicates reads:

01 Source 0 files · 0 B. Only the files you choose are compared. 02 Comparison Files 0 of 500 Total size 0 B of 2 GiB Compared by SHA-256 of the content 03 Result Groups of identical files are listed on the stage. Nothing is deleted. Nothing leaves this tab. Find exact duplicates Up to 500 files and 2 GiB in total · compared by their content, never moved or deleted

The same number, two different ceilings

Both tabs say 2 GiB. They do not mean the same thing by it.

In File hash the 2 GiB is a ceiling on one file: "One file of any type, up to 2 GiB". The panel takes a single file and returns a single checksum.

In Find duplicates the 2 GiB is a ceiling on the whole set: "Up to 500 files and 2 GiB in total". The panel takes up to 500 files, and 2 GiB is the ceiling on them added together, not on each one.

So on the second tab you can compare 500 files, but only while their combined size stays under 2 GiB. That is about 4 MiB per file if you use the full file count, and it is a ceiling on the batch, not a per-file allowance you can spend 500 times.

The algorithm difference nobody is told about

This is the part I would have missed without opening both panels.

File hash gives you a choice. Its second step is a picker with two options, SHA-256 and SHA-512, plus a line explaining the default: "SHA-256 is the common choice for published checksums." The action button even changes with the selection - it reads Calculate SHA-256 when SHA-256 is picked.

Find duplicates gives you no choice and no explanation. Its second step is called Comparison, not Algorithm, and its third line reads "Compared by SHA-256 of the content". There is no SHA-512 option in that panel, and there is no sentence saying why there is not one.

So if the checksum you need to match is a SHA-512, the duplicate finder cannot produce it. It groups by SHA-256 or it does not group at all. The panel does not refuse you, does not warn you and does not mention SHA-512 - it simply states the one algorithm it uses.

That is a real difference between the two tools sitting in the same tab strip, and the copy on the page is the only place you would learn it.

What the duplicate finder does and does not claim

Two lines in that panel are worth reading carefully, because they are narrower than the tab name suggests.

"Groups of identical files are listed on the stage. Nothing is deleted." - identical, and nothing is deleted.

"Up to 500 files and 2 GiB in total · compared by their content, never moved or deleted" - compared by content, so a renamed copy still groups, and never moved or deleted, so the tool only reports.

Both of those are the tool's own words, and they are the reason the tab is safe to run on a folder you care about: it reads, it groups, it lists, and it leaves your files exactly where they were. What it does not do is decide which copy you should keep - that is still your call, and for files that only look alike rather than being byte-identical, it will not group them at all.

The one thing I did not test

I read both panels in the live app today and I did not run a SHA-512 hash or a multi-file comparison in this run, so everything above is the panel copy and the structure of the two tools, not the output of a completed run. The hashing and grouping behaviour itself is covered in our earlier write-up of the Find duplicates tab.

If you need SHA-512 for a published checksum, use the File hash tab and pick it. If you need to know which of several files are byte-identical, Find duplicates does that by SHA-256 and will not do SHA-512 at all.

You can try both in the File Studio. Every app we make has a guide page as well, and they are all listed here.