Direct comparison
h-index vs i10-index — what is the difference?
The h-index and the i10-index are both author-level citation metrics. The h-index balances productivity and citation impact in a single number; the i10-index simply counts how many of an author's publications have at least ten citations. The i10-index is specific to Google Scholar.
Side-by-side comparison
| Dimension | h-index | i10-index |
|---|---|---|
| What it measures | A balance of productivity and per-paper citation impact | How many papers cleared a fixed 10-citation threshold |
| Definition | h papers each cited at least h times | Number of publications with at least 10 citations |
| Introduced | Jorge E. Hirsch, 2005 (PNAS) | Google Scholar, 2011 |
| Threshold | Self-adjusting — the value sets its own bar | Fixed — always 10 citations |
| Where it is reported | Scopus, Web of Science, Google Scholar, and others | Google Scholar profiles only |
| Sensitivity to a single highly-cited paper | Low — a single huge paper cannot raise h beyond the count of qualifying papers | Low — counts papers over the bar, not their size |
| Effect of career length | Rises over a career; never decreases | Rises over a career; never decreases |
| Database dependence | Value differs between Scopus, Web of Science, Google Scholar | Tied to Google Scholar's indexing |
| Field comparability | Not comparable across disciplines without normalisation | Not comparable across disciplines without normalisation |
Common questions
FAQ
Is a higher i10-index always better than a higher h-index?+
They are not interchangeable. The h-index ties productivity to sustained citation impact, while the i10-index just counts papers over a fixed bar of ten citations. An author can have a high i10-index from many modestly-cited papers but a lower h-index, so the two answer different questions.
Why is the i10-index only on Google Scholar?+
The i10-index was created by Google Scholar for its author profiles and is computed from Google Scholar's own index. Scopus and Web of Science report the h-index and their own indicators but do not display an i10-index.
Do both metrics have the same weaknesses?+
Largely yes. Both favour longer careers, ignore author position and contribution, are not comparable across disciplines, and depend on which citations the underlying database has indexed. Responsible-assessment frameworks caution against relying on either as a proxy for research quality.
