Name Cost Description Repositories
Altmetric Free with premium features - A data science company that tracks where published research is mentioned online, and provides tools and services to institutions, publishers, researchers, funders and other organisations to monitor this activity, commonly referred to as altmetrics. 28
Bielefeld Academic Search Engine Completely free - A search engine for academic web resources indexing the metadata of all kinds of academically relevant resources – journals, institutional repositories, digital collections etc… Service provided by the University of Bielefeld (Germany). 6
CAB Abstracts Premium only - CAB Abstracts is the leading English-language bibliographic information service providing access to the world’s applied life sciences literature. It comes with CABI Full Text, giving users automatic access to over 570,000 journal articles, conference papers and reports (80% of which are not available electronically anywhere else). 1
Chemical Abstracts Premium only - At CAS, we curate, connect, and analyze scientific knowledge to reveal the unseen connections that inspire breakthroughs. We weave a fabric of discovery that scientific innovators can tap into to stimulate their creativity and accelerate their work. Because when the world turns to science, science turns to CAS. 1
CORE Completely free - One of the world’s largest collections of open access full texts, which are used and referenced by people globally, including researchers, libraries, software developers, funders and many more. CORE content covers all research disciplines and comes from thousands of institutional and subject repositories and journals. CORE is a not-for-profit service delivered by The Open University and Jisc. 3
Crossref Free with premium features - Crossref makes research objects easy to find, cite, link, assess, and reuse. We’re a not-for-profit membership organization that exists to make scholarly communications better. 13
DART Europe Completely free - DART-Europe was founded in 2005 as a partnership of national and university libraries and consortia to improve global access to European research theses. The DART-Europe E-theses Portal is managed by UCL Library Services. 1
DBLP Completely free - The dblp computer science bibliography provides open bibliographic information on major computer science journals and proceedings. Originally created at the University of Trier in 1993, dblp is now operated and further developed by Schloss Dagstuhl. 1
Dimensions Free with premium features - Database and search engine of articles and preprints 1
Disqus Free with premium features - The internet's favorite comment plug-in makes it easy for publishers to bring their content to life, fuel colorful discussions, efficiently moderate comments, and build engaged communities. 3
Ebsco - 1
EconLit Completely free - Professionally classified, updated weekly, and including over 1.6 million records, EconLit covers economics literature published over the last 130 years from leading institutions in 74 countries.  In combination with the optional full-text package of over 500 journals, including the prestigious AEA journals, EconLit provides a comprehensive library of economics literature. 1
eLife Completely free - An OA journal proposing to publish peer-reviews of preprints submitted to e-Life, whatever the outcome of the evaluation 2
Episciences Completely free - Episciences is a platform for overlay journals. The ambition is to provide the scientific communities with the technical means to produce quality journals, at a lower cost, widely accessible, by relying on open archives (Diamond Model). The submission of an article to a journal is done by a prior deposit of a preprint in an open archive. Episciences provides a website for each overlay journal. The articles are available in open access via the journal website and on the original Archive, whether or not it is accepted by the journal. Once the preprint has been peer-reviewed and accepted by the journal, the open archive used for the submission of the manuscript is updated with the publication references 3
Europe PMC Completely free - Database and search engine of articles and preprints 15
Google Completely free - General search engine 1
Google Analytics Free with premium features - Get a complete understanding of your customers across devices and platforms. Google Analytics gives you the tools, free of charge, to understand the customer journey and improve marketing ROI. 1
Google Scholar Completely free - All kind of documents (books, reports, articles, preprints) 69 Completely free - A system allowing annotation of web pages. It uses a browser plug-in or a bookmarklet (others), or it is viewable without needing a plug-in in some websites (eg biorxiv). 20
ISIDORE Completely free - An online platform that allows research and access to human and social sciences digital data. 1
ithenticate Premium only - iThenticate is the premier tool for researchers and professional writers to check their original works for potential plagiarism. 5
Leibniz Open Completely free - 1
Lens Free with premium features - Lens serves global patent and scholarly knowledge as a public good to inform science and technology enabled problem solving. No account required. 1 Completely free - A simple authoring tool for complex documents. 1
meta Completely free - All kind of documents (books, reports, articles, preprints) 1
Microsoft Academic Completely free - Microsoft Academic is a project exploring how to assist human conducting scientific research by leveraging machine’s cognitive power in memory, computation, sensing, attention, and endurance. 25
NASA Astrophysics Data System Completely free - 1
OAIster Completely free - OAIster is a union catalog of millions of records that represent open access resources. This catalog was built through harvesting from open access collections worldwide using the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH). Today, OAIster includes more than 50 million records that represent digital resources from more than 2,000 contributors. 2
OpenAire explore Completely free - A search engine for datasets, publications, preprints, research softwares, funders, funding grants… Supported by the European Union. 6 - 1
Overleaf Free with premium features - Free with basic options. Allows to write and edit collaboratively latex documents with various templates including journal templates. ShareLaTex is now integrated in Overleaf2. 4
Peer Community in Completely free - A community of scientists and researchers and a platform for assessing through open peer-review and possibly recommending preprints submitted by authors. No costs implied for users. Authors submit their preprints to get a recommendation after peer-reviews and editorial decisions. The recommendation is published by the PCI together with all peer-review material. However, the service does not publish the article because which stays on the preprint server and/or may be submitted to a journal (the decision is made by the authors). 10
Peerage of Science Completely free - PoS operates upstream from the publication system and provides support to existing scientific journals. Its revenues come from organizations wishing to purchase the peer review service. 2
Plaudit Completely free - Plaudit allows researchers, identified by their ORCID, to put positive flags on articles they endorse, identified by their DOI in the publisher website. 24
PlumX Metrics Completely free - An online tool that provides altmetrics for peer-reviewed journal articles and other scholarly works by aggregating information from different sources. 4
Prepubmed Completely free - Search engine of preprints 11
PREreview Completely free - A community and platform for the collaborative writing of preprint reviews. It gathers journal clubs providing feedback to authors but it also publishes reviews (of preprints) written by any researcher with an Orcid iD. Authors do not submit their own preprints to PREreview for evaluation. 2
Proquest Premium only - ProQuest is committed to empowering researchers and librarians around the world. The company's portfolio of assets - including content, technologies, and deep expertise - drives better research outcomes for users and greater efficiency for the libraries and organizations that serve them. 1
Publons Completely free - A searchable index of all COVID-19 papers and preprints, updated daily. 1
PubMed Completely free - Database and search engine of articles and preprints (only those funded by NIH) 5
PubPub Completely free - PubPub is an open-source, hosted, free-to-use content management system designed to help knowledge communities of all types collaboratively create and share knowledge online. PubPub’s flexible, extensible system allows communities to create the dynamic content that best represents their work, whether it’s a traditional academic journal, a book, a repository of interactive documents, a blog, all of the above, or something in between. If needed, PubPub then helps communities integrate their work into academic infrastructure like Crossref and Google Scholar without the need to remake it to conform to legacy expectations of how academic outputs are structured. 1
RePEc Completely free - RePEc (Research Papers in Economics) is a collaborative effort of hundreds of volunteers in 102 countries to enhance the dissemination of research in Economics and related sciences. The heart of the project is a decentralized bibliographic database of working papers, journal articles, books, books chapters and software components, all maintained by volunteers. The collected data are then used in various services that serve the collected metadata to users or enhance it. 2
Research Square Completely free - Indicates whether a preprint is currently under review in a journal. 1
Researcher App Completely free - Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free. 2
Researchgate Completely free - A European commercial social networking site for scientists and researchers[3] to share papers, ask and answer questions, and find collaborators. 1
Review Commons Completely free - A platform that peer-reviews preprints before submission to a journal, provides authors with a Refereed Preprint, which includes the authors’ manuscript, reports from a single round of peer review and the authors’ response. The refereed preprint is then sent to bioRxiv and affiliate journals. 2
scanR Completely free - scanR allows you to search for companies active in research and innovation, public research laboratories, public funding, research work (publications, PhD dissertations). ScanR identifies the links between these different objects and allows to describe them in their context. For example, scanR can instantly provide a mapping of research collaborations of a laboratory or any other institution. 1
ScienceOpen Completely free - Offers open access journal hosting services, as well as advanced indexing and promotional services that showcase customer content within the discovery platform. Every research article on ScienceOpen has a traceable genealogy through citations, a public peer review process, and social interaction tracked by altmetrics, which they call research "context". ScienceOpen appoints members of the research community as Collection Editors who curate articles from multiple publishers in any topic. Collections support discovery of and within research communities. All content on the platform is available for post-publication peer review by scientific members with five or more peer-reviewed publications on their ORCID, and all articles can be publicly commented on by members with one or more items. 1
Scilit Completely free - Scilit is a free and comprehensive content aggregator platform for scholarly publications. 12
Scite Free with premium features - A service to find citation of your article (preprint) in its context + categorization into “mention”, “support”, “dispute”. To pay. 1
Scopus Free with premium features - Scopus uniquely combines a comprehensive, expertly curated abstract and citation database with enriched data and linked scholarly literature across a wide variety of disciplines. 4
SHARE Completely free - SHARE’s open API tools and services help bring together scholarship distributed across research ecosystems for the purpose of greater discoverability. However, SHARE does not guarantee a complete aggregation of searched outputs. For this reason, SHARE results should not be used for methodological analyses, such as systematic reviews. 24
Software heritage Completely free - Collect, curate and preserve software in source code form. 1
Unpaywall Completely free - An open database of 32,073,031 free scholarly articles. We harvest Open Access content from over 50,000 publishers and repositories, and make it easy to find, track, and use. 23
WorldCat Completely free - WorldCat is the world's most comprehensive database of information about library collections. Unique in scale and unparalleled in data quality, WorldCat makes library collections findable and accessible around the world. It's where you can locate a book, video, or other item of interest and discover which libraries near you own the item. Individual member libraries in your community and elsewhere provide access to the items represented in WorldCat. 3