How to Use OpenAlex to Find Free PDFs and Convert to EPUB
OpenAlex is the fastest-growing free alternative to Scopus and Web of Science — 250 million scholarly works, completely free, with a powerful API. No institutional access required. When you find papers worth reading, converting the PDF to EPUB makes them far more comfortable on any e-reader.
What is OpenAlex?
OpenAlex (openalex.org) was launched in 2022 by OurResearch as a replacement for Microsoft Academic Graph. Key features:
- 250+ million scholarly works — more coverage than Scopus or Web of Science
- Completely free — web interface and API, no account required for basic use
- Open access detection — powered by Unpaywall, links to free PDFs where available
- Free API — search, filter, and export results programmatically
- Topic classification — papers tagged by field, concept, and domain
- Citation graph — forward and backward citations for any paper
Searching and finding PDFs
- Go to openalex.org
- Search by title, author, topic, or institution
- Filter results by Open Access to show only freely downloadable papers
- Click any paper → look for the green PDF button or Open Access link
- Download the PDF directly
OpenAlex shows the open-access version for roughly 50% of papers — the same coverage as Unpaywall (which powers OpenAlex's OA detection).
Converting to EPUB
- Go to pdf2epub.toolkit.bot
- Upload the PDF found via OpenAlex
- Wait ~30 seconds
- Download the EPUB and transfer to your e-reader
Using the OpenAlex API for bulk PDF discovery
The OpenAlex API is free and powerful for systematic literature workflows:
# Find open-access papers on a topic with PDF links
https://api.openalex.org/works?filter=topic.id:T11475,open_access.is_oa:true&per-page=50Each API result includes open_access.oa_url — the direct PDF link. A short Python script can download all PDFs, and the toolkit.bot API can convert them to EPUB in bulk. This is useful for systematic reviews needing full-text access to hundreds of papers.
OpenAlex vs Scopus and Web of Science
| OpenAlex | Scopus | Web of Science | |
|---|---|---|---|
| Cost | Free | Subscription | Subscription |
| Records | 250M+ | 90M+ | ~90M |
| Open access PDFs | Yes (via Unpaywall) | Partial | Partial |
| API access | Free, generous limits | Paid API | Paid API |
| Formal h-index | Accepted at some institutions | Gold standard | Gold standard |
| Best for | Discovery, OA systematic reviews, API workflows | Citation analysis, formal metrics | Historical coverage, impact factors |
Frequently asked questions
What is OpenAlex?
OpenAlex is a free, open-source scholarly graph of 250+ million research works, built by OurResearch (the same team behind Unpaywall). It was created in 2022 as a replacement for the discontinued Microsoft Academic Graph, designed to be the open-science alternative to Scopus and Web of Science. OpenAlex is completely free — no subscription, no institutional access needed. It provides a web interface (openalex.org) and a free API for programmatic access.
How does OpenAlex compare to Scopus and Web of Science?
OpenAlex covers more records (250M+) than either Scopus (90M+) or Web of Science (~90M) because it indexes preprints, grey literature, and smaller publishers not covered by the commercial databases. It's less curated — quality varies more than in Scopus/WoS. For researchers without institutional access to Scopus or WoS, OpenAlex is an excellent free alternative for literature searches and citation analysis. For h-index calculations used in formal evaluation, Scopus or WoS are still preferred by most institutions.
Does OpenAlex provide PDF downloads?
OpenAlex shows open-access status for every paper and links to free PDF versions where available. Look for the 'Open Access' tag and PDF link on any paper page. OpenAlex uses data from Unpaywall, so it finds the same legal free PDFs. For papers without free access, OpenAlex shows the publisher link (institutional access required). The API can filter results to only open-access papers — useful for systematic reviews where you need full-text access to all papers.
Can I use OpenAlex API for systematic literature reviews?
Yes — OpenAlex has a free REST API (api.openalex.org) with generous rate limits. You can filter by topic, year, citations, open-access status, institution, and funder. It returns full metadata including open-access PDF URLs. Many researchers use OpenAlex API alongside R packages (openalexR) or Python clients (pyalex) for automated literature searching. This is particularly useful for systematic reviews where you need to search thousands of papers programmatically.
Is OpenAlex data reliable enough for academic citation analysis?
OpenAlex is increasingly reliable for most citation analysis purposes. It's used by many universities and funding agencies. Some limitations: citation counts may differ slightly from Scopus/WoS (different coverage), disambiguation of author names can have occasional errors, and some specialized journals may have incomplete coverage. For informal analysis, literature discovery, and systematic reviews, OpenAlex is excellent. For formal h-index reporting or journal ranking (used in hiring/tenure decisions), institutions typically require Scopus or WoS.