Best Websites For Research Papers Free: Top Picks

1. Top Academic Search Engines

Academic search engines filter only scholarly, peer-reviewed content, offering reliable alternatives to general search engines.

1.1 Google Scholar

Overview: Indexes journal articles, theses, books, and conference papers.
Strength: Links directly to open-access PDFs and institutional repositories.
Tip: Add “filetype: pdf” to search queries to locate free versions.
(Martín-Martín et al., 2018)

1.2 CORE

papers, pulling content from 10,000+ repositories globally.
Strength: Every record links to a free full-text file.
Tip: Use the “Repository filter” to find content from leading universities.
(CORE, 2025)

1.3 Semantic Scholar

Overview: Developed by the Allen Institute for AI, this platform uses natural language processing to generate research summaries and highlight key citations.
Strength: Shows citation context, influence scores, and often provides direct links to PDFs.
(Ammar et al., 2018)

1.4 BASE (Bliefield Academic Search Engine)

Overview: Managed by Bielefeld University Library (Germany), BASE indexes 300+ million academic documents from open repositories.
Strength: Provides advanced search filters by content type, language, and access rights.
Tip: Limit to “open-access only” for free full texts.
(Pieper & Summann, 2024)

2. Open-Access Repositories and Journal Directories

These repositories and directories ensure permanent free access to peer-reviewed journals, literature, and preprints.

2.1 arXiv

Focus: Physics, mathematics, computer science, and quantitative biology.
Strength: Rapid dissemination of preprints long before journal publication.
Note: Preprints are not peer-reviewed but later appear in journals.
(Larivière et al., 2023)

2.2 PubMed Central (PMC)

Focus: Biomedical and life sciences research.
Strength: Maintained by the U.S. National Institutes of Health, ensuring long-term archiving and compliance with open-access mandates.
(NIH, 2025)

2.3 DOAJ – Directory of Open Access Journals

Focus: Curated database of over 20,000 peer-reviewed open-access journals across all disciplines.
Strength: Rigorous selection criteria and verified licensing (Creative Commons).
(DOAJ, 2025)

2.4 PLOS (Public Library of Science)

Focus: High-impact open-access publishing in medicine, biology, and social sciences.

Strength: Publishes research under CC BY license for maximum reuse.
(PLOS, 2025)

These communities connect researchers globally, promoting knowledge sharing and open access.

3.1 ResearchGate

Overview: A social network where researchers upload papers, datasets, and preprints.
Strength: Many authors share free, post-print copies of their articles.
Tip: Look for the “Full-text available” badge.
(Thelwall & Kousha, 2017)

3.2 Academia.edu

Overview: Academics upload their work, follow others, and track readership.
Strength: Excellent for humanities and social science fields.
Note: the authors upload PDFs to ensure legality and free access.

Best Websites for Research Papers — Free Access

1️⃣ Academic Search Engines

Google Scholar: Finds PDFs and preprints, tracks citations, and connects to open repositories.

CORE: Aggregates 300M+ open-access research papers globally.

Semantic Scholar: AI-powered search summarizing key research points.

BASE: Indexes 300M+ academic documents from repositories worldwide.

2️⃣ Open-Access Databases

arXiv: Preprints in physics, math, CS, and related sciences.

PubMed Central: NIH’s full-text archive for life sciences and medicine.

DOAJ: Curated directory of open-access journals.

PLOS: Peer-reviewed open-access scientific journals.

3️⃣ Social & Collaborative Platforms

ResearchGate: Free uploads of author-approved PDFs.

Academia.edu: Network for researchers sharing open versions of papers.

Unpaywall / PaperPanda: Extensions that locate free legal versions automatically.

4. Browser Extensions and Tools

Browser-based tools automatically locate free versions of paywalled research papers.

Tool	Function	Source Type	Cost
Unpaywall	Finds legal OA versions in repositories.	Journal & repository links	Free
PaperPanda	Locates PDFs from OA sources with one click.	arXiv, DOAJ, CORE	Free
Open Access Button	Finds public or author-uploaded copies.	Institutional repositories	Free

5. Other Strategies for Free Access

Even when articles are paywalled, several legitimate alternatives can help:

Email the author directly: Most researchers share a personal copy upon request.
Add “PDF” to Google search: e.g., “Cognitive load in PhD writing PDF”.
Check university repositories: Many theses and dissertations are publicly available under institutional open-access mandates.
Use national consortia: In India, for instance, INFLIBNET and Shodhganga offer free academic content for registered users.

Platform	Type	Access	Ideal For	Peer-Reviewed
Google Scholar	Search engine	Free/Partial	General academia	Mixed
CORE	Aggregator	100% Free	All disciplines	Mixed
Semantic Scholar	AI-powered	Free/Partial	STEM, interdisciplinary	Mixed
BASE	Indexer	100% Free	Institutional papers	Mixed
arXiv	Repository	100% Free	STEM preprints	No
PubMed Central	Repository	100% Free	Medicine, biology	Yes
DOAJ	Directory	100% Free	Peer-reviewed journals	Yes
ResearchGate	Social network	Free	Multidisciplinary sharing	Mixed

9 Best Research Paper Search Engines

How To Check Scopus-Indexed Journals: Step-By-Step

Where To Read Research Papers For Free

Best Websites For Research: Type-Specific Guide

FAQs

Where can I find free research papers online?

You can find free research papers through open-access databases and academic search engines like Google Scholar, CORE, DOAJ, and Semantic Scholar. For subject-specific areas, PubMed Central (biomedical) and arXiv (STEM) provide free full-text access to peer-reviewed and preprint papers.

What is the difference between open-access and free access?

Open-access papers are permanently free to read, share, and reuse under a license (such as Creative Commons).
Free-access papers may be temporarily or partially free (for example, through publisher promotions). For long-term reliability, prefer open-access repositories like DOAJ or institutional archives.

What are the best websites to download free research papers by field?

STEM: arXiv, PubMed Central, and IEEE Xplore (open portions)
Social Sciences & Humanities: SSRN, ResearchGate, and Academia.edu
Multidisciplinary: Google Scholar, Semantic Scholar, and CORE

Can I use free research papers in my thesis or dissertation?

Yes—free research papers can be cited and referenced in academic work, provided they come from legitimate, peer-reviewed, or credible open-access sources. Always include proper citations with author names, titles, journal names, and DOI links to maintain academic integrity.

Conclusion

The growing open-access movement ensures that knowledge remains a global public good. Tools like CORE, DOAJ, and PubMed Central have democratized academic access, while Google Scholar and Semantic Scholar connect researchers to both open and subscription content.

For the most efficient workflow:

Use Google Scholar + Unpaywall for discovery and free access.
Explore CORE and BASE for repository-based literature.
Supplement with ResearchGate or Academia.edu for author-posted copies.

By combining these strategies, even independent scholars can access a vast collection of research papers without paywalls—a significant step toward equitable academic research.

References

Martín-Martín, A., Orduna-Malea, E., Thelwall, M., & López-Cózar, E. D. (2018). Google Scholar, Web of Science, and Scopus: A systematic comparison of citations. Journal of Informetrics, 12(4), 1160–1177. https://doi.org/10.1016/j.joi.2018.09.002
Ammar, W., Groeneveld, D., Bhagavatula, C., et al. (2018). Construction of the Semantic Scholar corpus. Proceedings of LREC 2018.
Pieper, D., & Summann, F. (2024). BASE: Global indexing of open-access repositories. Bielefeld University Press.
Larivière, V., Sugimoto, C. R., & Haustein, S. (2023). The impact of preprints on scholarly communication. Scientometrics, 128(3), 2345–2367. https://doi.org/10.1007/s11192-023-04777-9
NIH. (2025). PubMed Central Overview. https://www.ncbi.nlm.nih.gov/pmc/
DOAJ. (2025). Directory of Open Access Journals — About. https://doaj.org/
PLOS. (2025). Open Access Publishing. https://plos.org/
Thelwall, M., & Kousha, K. (2017). ResearchGate: Disseminating and communicating scholarly output. Journal of the Association for Information Science and Technology, 68(4), 1029–1036.
Unpaywall. (2025). Find open-access papers instantly. https://unpaywall.org/
OA Button Project. (2024). Open Access Button: Access research legally. https://openaccessbutton.org/

About The Author

Navjyot Gill

After a career in biochemistry and molecular biology, I now dedicate this ResearchDeep platform to simplifying Master’s and PhD research to assist postgraduate researchers worldwide. To know more, visit the ABOUT page.

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