An ORCID iD is a free, persistent, unique identifier for a researcher, the academic equivalent of a passport number for your scholarly work. It is sixteen characters in four hyphenated groups of four, for example 0000-0002-1825-0097, and journals, funders and universities use it to link papers, grants and datasets to the right person even when names are common or change. This tool checks the arithmetic of an iD; it does not look the person up in the registry.

Why does the last character of an ORCID sometimes show an X?

The sixteenth character is a check digit computed from the first fifteen with ISO 7064 MOD 11-2. That algorithm can produce a value of ten, which will not fit in a single decimal slot, so the standard writes ten as the letter X. The iD 0000-0002-9079-593X is therefore perfectly valid, with X meaning the check value is ten. X is only ever legal in the final position, never anywhere else in the iD.

How is the ORCID check digit calculated?

Start a running total at zero. For each of the fifteen body digits left to right, add the digit to the total then multiply the total by two. After the last digit, the check value is (12 minus total modulo 11) modulo 11. If that value is ten it is written X, otherwise it is the digit itself. For 0000-0002-1825-009 the math lands on 7, so the full iD is 0000-0002-1825-0097. Switch to the complete tab to see this run on your own digits.

Does the hyphen formatting matter?

The hyphens are only for human readability and the math ignores them entirely. 0000-0002-1825-0097, 0000000218250097 and https://orcid.org/0000-0002-1825-0097 are all the same iD and all validate the same way. ORCID does ask that you display the iD as a full https://orcid.org/ URL in published work, and the tool gives you that exact URL with a copy button next to the bare canonical form.

If an ORCID passes the check, does the researcher actually exist?

No. A valid check digit only proves the sixteen characters are mutually consistent, which catches single typos and most transposed-digit mistakes. It says nothing about whether that iD was ever registered to a real person. A made-up string can pass the arithmetic by chance. To confirm a live record you would open the iD at orcid.org and read the profile; this tool deliberately stays offline and only answers the math, so it works with no network and leaks nothing.

Can I validate many ORCID iDs at once?

Yes. Open the batch tab and paste one iD per line, mixing hyphenated, bare and URL forms freely. Each line is checked on its own, blank lines are skipped, and a summary tells you how many of the list pass. It is handy for cleaning an author export, a grant report or a co-author spreadsheet before you submit, since one bad check digit usually means a digit was dropped or swapped during copy and paste.

Clean an author list before submitting a paper

You are assembling the byline for a multi-author manuscript and each co-author pasted their ORCID into a shared doc. Drop the whole list into the batch box: any iD whose check digit fails was almost certainly mistyped or truncated during copy and paste. Fix those rows before the submission system rejects the whole upload, and you avoid a round of emails asking three people to resend their iD.

Validate ORCIDs in a grant or repository import

A funder portal or institutional repository wants ORCID iDs for every named investigator, and a bad one stalls the import. Run your export through the batch check first so a dropped digit shows up on your screen, not in a cryptic validation error halfway through a fifty-row upload that you then have to debug line by line.

Finish or generate a check digit for test data

You are building a form that accepts ORCID iDs and need realistic fixtures, or you have the first fifteen digits of a code and want the one correct check digit. Switch to the complete tab, type the fifteen digits, and the tool returns the MOD 11-2 check character and the full canonical iD, so your test cases pass your own validator for the right reason rather than by luck.

Teach or learn the ISO 7064 algorithm

You are explaining check-digit schemes or modular arithmetic and want a live, well-known example. Type any iD, change one digit, and watch the verdict flip; the derivation note spells out exactly how the running double-and-add works and why the value ten is written X, so the algorithm stops being a black box and becomes something a student can reproduce by hand.

ORCID Validator and Check Digit Calculator

Check an ORCID iD check digit with ISO 7064 MOD 11-2, complete the check digit from the first 15 digits, validate a whole list, all in your browser

Runs locally
Category Developer & DevOps
Best for Formatting, validating, shrinking, or inspecting code-adjacent text.

Note: A valid check digit only means the iD is internally consistent — it catches typos and digit swaps. It does NOT confirm the ORCID was ever registered to a real researcher. This tool never contacts the ORCID registry.

ORCID iD to check

Hyphens, spaces and the orcid.org URL prefix are ignored.

Enter an ORCID iD above to see validity and its canonical form.

What this tool does

A free ORCID iD validator that checks the check digit of a researcher ORCID using the ISO 7064 MOD 11-2 algorithm. An ORCID iD is sixteen characters written in four groups of four, such as 0000-0002-1825-0097, and the sixteenth character is a check digit that may be a digit 0 to 9 or the letter X when the computed value is ten. Paste an iD with or without hyphens, with or without the https://orcid.org/ prefix, and the tool strips the formatting, recomputes the check digit and tells you whether the iD is internally consistent. It also runs the other direction: type the first fifteen digits and it returns the one correct check digit that completes a valid iD, so you can finish a partial code or generate test data. A batch box checks a whole list one per line and reports how many pass. The result panel shows the characters read, the expected check digit and the check digit your input carried, so a mismatch is obvious. The canonical 0000-0000-0000-0000 form and the full ORCID URL both come with a one-click copy. Everything is plain JavaScript in the page and a shareable link reopens your exact iD. 100 percent client-side, nothing uploaded, and the ORCID registry is never contacted.

Tool details

Input: Files + Text; The page exposes text boxes, numeric controls, file pickers, or structured inputs depending on the tool.
Output: Live result + Copy; The result area focuses on usable output, with copy, download, or preview actions when supported.
Privacy: Browser-side processing; The main tool logic does not call an external API, so inputs normally stay in the current tab.
Save / share: Shareable URL state; Key settings are encoded in the URL so another person can reopen the same setup.
Performance budget: Initial JS <= 9 KB; No WASM budget is declared, keeping the tool quick to open on mobile.
Best fit: Developer & DevOps · Developer; Category and role tags drive related tools, internal links, and quick fit checks.

How to use

1. Input

Paste or drop your content into the tool panel.
2. Process

Click the button. All processing is local in your browser.
3. Copy / Download

Copy the result or download to disk in one click.

How ORCID Validator fits into your work

Use it in the small gaps between coding, reviewing, debugging, and shipping.

Developer jobs

Formatting, validating, shrinking, or inspecting code-adjacent text.
Preparing snippets for documentation, tickets, commits, or handoff.
Checking a small payload quickly without switching tools.

Developer checks

Run irreversible transforms like minify or obfuscate on a copy.
Keep secrets out of pasted snippets unless the tool explicitly stays local.
Use your normal tests or linter before shipping transformed code.

Good next steps

These links move the current task into a more complete workflow.

Real-world use cases

Clean an author list before submitting a paper
You are assembling the byline for a multi-author manuscript and each co-author pasted their ORCID into a shared doc. Drop the whole list into the batch box: any iD whose check digit fails was almost certainly mistyped or truncated during copy and paste. Fix those rows before the submission system rejects the whole upload, and you avoid a round of emails asking three people to resend their iD.
Validate ORCIDs in a grant or repository import
A funder portal or institutional repository wants ORCID iDs for every named investigator, and a bad one stalls the import. Run your export through the batch check first so a dropped digit shows up on your screen, not in a cryptic validation error halfway through a fifty-row upload that you then have to debug line by line.
Finish or generate a check digit for test data
You are building a form that accepts ORCID iDs and need realistic fixtures, or you have the first fifteen digits of a code and want the one correct check digit. Switch to the complete tab, type the fifteen digits, and the tool returns the MOD 11-2 check character and the full canonical iD, so your test cases pass your own validator for the right reason rather than by luck.
Teach or learn the ISO 7064 algorithm
You are explaining check-digit schemes or modular arithmetic and want a live, well-known example. Type any iD, change one digit, and watch the verdict flip; the derivation note spells out exactly how the running double-and-add works and why the value ten is written X, so the algorithm stops being a black box and becomes something a student can reproduce by hand.

Common pitfalls

Treating the X as a stray letter to delete. In an ORCID the trailing X is the check value ten and is part of the iD; removing it or replacing it with a zero breaks validation. X is only valid in the very last position, never inside the four-digit groups.
Confusing a valid check digit with a real, registered researcher. The math only proves the sixteen characters are self-consistent. A coincidental string can pass; to confirm a live profile you must open the iD on orcid.org, which this offline tool never does.
Dropping or doubling a digit during copy and paste, then assuming the iD is fine because it looks about right. A single missing digit shifts everything and fails the check, which is exactly what this tool is for. Run the iD through before you rely on it rather than after a system rejects it.

Privacy

Everything happens in your browser tab as plain JavaScript: the check-digit math, the batch validation and the canonical formatting. No ORCID you type is sent anywhere, the ORCID registry is never contacted, and nothing is logged. The one caveat is that the shareable link encodes your iD in the query string, so pasting a share link into a chat will record that iD in the recipient server access log. For an iD you would rather not leave a trace, use the copy button and paste the result instead of sharing the URL.

FAQ

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ORCID Validator and Check Digit Calculator

What this tool does

Tool details

How to use

1. Input

2. Process

3. Copy / Download

How ORCID Validator fits into your work

Developer jobs

Developer checks

Good next steps

Real-world use cases

Clean an author list before submitting a paper

Validate ORCIDs in a grant or repository import

Finish or generate a check digit for test data

Teach or learn the ISO 7064 algorithm

Common pitfalls

Privacy

FAQ

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