Free

In scenarios where you would not want to publish your paper into expensive journals, you can deposit them in these free repositories. Unlike proper paper submission, you need to associate yourself to an institution such as IEEE, university, etc. However, after long usage of free publications, I would recommend the following options.

There are more free repository available for use but generally I would stick to the list. The higher the list, the better my recommendation to you. Those that were not mentioned either has bad / a lot of grey area in their business operations OR simply I have not use it at all.

Tips To Maximizes Audience Reach

Normally for sensitive and frontier researches, you would not consider these free channels as your institution is already having its own publication channels. Some may even consider the research as trade secrets.

However, normally these free channels are great for your own researches or sharing data. For that purpose, you would want to:

  1. Get a DOI URL from a publisher (I recommend Zenodo as a start)
  2. Once done, you can use that DOI URL to republish onto other platforms. While filling up the publication, do remember to fill that DOI into it. That way, you can have maximum reach across all networks while maintaining a clean publication process.
Zenodo Logo

Zenodo

Zenodo.org (https://zenodo.org) is an open-source digital library built upon Invenio that enables anyone (including non-institution associated individuals) to contribute into Open Science. It is funded by European Commission (EC) CERN division. All publications are indexed in OpenAIRE.

Open Science knows no border so anyone in the world can contribute into its repository.

The Pros

  1. 50GB max limit per publications with a designated document object identifier (DOI) with Zenodo tag.
  2. Has a lot of independent fields for search advantages
  3. ORCID linked.
  4. No strict requirement on paper format.
  5. Funded by EU CERN, OpenAIRE, and European Council.

The Cons

  1. Its headquarter is in Europe, under EC controls.
  2. Strictly Creative Common version 4 license.
  3. Does not perform sharing on-behalf (need manual reach).

Academic.edu

Academia.edu (https://www.academia.edu/) is a paper sharing network for research community, allowing unconventional paper sharing across the globe. It was the first well-known network that every scholars and academic staffs to use.

The Pros

  1. Can achieve great reach without incurring much cost.
  2. Interactive communities.
  3. free document object identifier (DOI) with Academia Tag.
  4. No strict requirement on paper format.

The Cons

  1. Lagging and slow, possibly due to a lot of users and overloaded the infrastructure.
  2. It is privately funded, for-profit organization.
  3. Not ORCID linked. However, You can publish your ORCID on your profile.
  4. Bombarded with loads of advertisements.

ResearchGate

ResearchGate.net (https://www.researchgate.net) is social network for scientific community, allowing any individual to publish any kinds of data and papers on your profile. It is privately funded by multiple investors like Series C venture capital and Bill Gates himself.

The Pros

  1. Well organized, well presented, and networked across all researchers and authors
  2. Open licenses, including support of private files.
  3. free document object identifier (DOI) with ResearchGate tag.
  4. No strict requirement on paper format.

The Cons

  1. Well known for spamming all your co-authors with invitations email under your name.
  2. It is privately funded, for-profit organization.
  3. Weird indexing like RG Score that makes no sense.
  4. Limit per publications to 512MB. Special arrangement is required if needed larger size.
  5. Not ORCID linked. However, You can publish your ORCID on your profile.

That's all about free repository for publications.