Crossref

Monthly works registered with Crossref by DOI-creation date since 2015: the all-works baseline, AI title slices and their share, named models, preprints, retraction notices, and AI vocabulary counts.

We count a work in the month a publisher registered its DOI with Crossref, not in the month of publication.

cadence · monthly 12 series updated 22 Jul 2026 www.crossref.org ↗

release markers

All works

1.1M +12.9% yr as of Jun 2026

Publishers sometimes register many old works at once, so one month can jump high and the share lines dip that month.

AI title share

Crossref's title search ignores the quotes, so it also finds titles with only one of the two words. These counts are too high, so read the growth and not the total.

"artificial intelligence" in title

12.3k +43.9% yr as of Jun 2026

Named models

ChatGPT in title

566 −10.7% yr as of Jun 2026

DeepSeek in title

95 +31.9% yr as of Jun 2026

Copilot in title

40 −11.1% yr as of Jun 2026

This line mixes GitHub Copilot with Microsoft 365 Copilot.

Grok in title

12 +100.0% yr as of Jun 2026

About 10 works a month. Read presence and absence, not the month-to-month movement.

Publication type

Preprints

66.0k +49.6% yr as of Jun 2026

Preprints with a DOI from Crossref — bioRxiv, SSRN, Research Square. arXiv registers its DOIs with DataCite, so this line does not count arXiv.

Preprint share of all works derived

5.9% of works +32.5% yr as of Jun 2026

Preprints ÷ all works, so this is the preprint share of everything with a Crossref DOI.

Research integrity

Retraction notices

387 +14.5% yr as of Jun 2026

This line counts retraction notices in the month the publisher registered the notice. A notice from 2026 can retract a paper from 2014.

Retraction notices per 100k works derived

34.3 +1.4% yr as of Jun 2026

Notices this month ÷ new DOIs this month × 100k. ⚠ The notices are about older papers, so this is not the share of papers that publishers retract.

AI vocabulary

LLM in title

1.8k +112.9% yr as of Jun 2026

"transformer" in title

2.5k +59.8% yr as of Jun 2026

⚠ This search also finds electrical power transformers — 147 works in June 2018, before the AI sense of the word. Only the growth is about AI.

Figures

Series	Latest	Change	Min	Max	Coverage
All works	1.1M	+12.9% yr	468k	2.6M	Jan 2015 — Jun 2026
"artificial intelligence" in title	12.3k	+43.9% yr	824	12.3k	Jan 2015 — Jun 2026
ChatGPT in title	566	−10.7% yr	0	809	Jan 2015 — Jun 2026
Preprints	66.0k	+49.6% yr	428	247k	Jan 2015 — Jun 2026
Retraction notices	387	+14.5% yr	110	2.7k	Jan 2015 — Jun 2026
LLM in title	1.8k	+112.9% yr	0	1.8k	Jan 2015 — Jun 2026
"transformer" in title	2.5k	+59.8% yr	82	2.6k	Jan 2015 — Jun 2026
DeepSeek in title	95	+31.9% yr	0	115	Jan 2015 — Jun 2026
Copilot in title	40	−11.1% yr	0	48	Jan 2015 — Jun 2026
Grok in title	12	+100.0% yr	0	17	Jan 2015 — Jun 2026
Preprint share of all works	5.9%	+32.5% yr	0.1%	22.8%	Jan 2015 — Jun 2026
Retraction notices per 100k works	34.3	+1.4% yr	16.7	261.3	Jan 2015 — Jun 2026

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