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Research · head to head

Mendeley vs Obsidian

Mendeley logo

Mendeley

Research

The free all-in-one reference manager

From
Free
Rated
-
Full reviewWebsite
Obsidian logo

Obsidian

Research

A powerful knowledge base on top of a local folder of plain text Markdown files

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Mendeley free tier limited to 5 Reading Assistant questions per month and 2GB storage; Obsidian sync is a paid add-on at $4 per month billed annually rather than part of the app
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Mendeley and Obsidian actually diverge.

Attributes where Mendeley and Obsidian differ
AttributeMendeleyObsidian
Pricing modelfreemiumUnknown
PlatformsWebWeb, Windows, macOS, Linux, iOS, Android
FoundedUnknown2020

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated), category (Research).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Mendeley

Nothing recorded that Obsidian does not also cover.

Only in Obsidian

  • Bidirectional linking
  • Graph view visualization
  • Markdown support
  • Local file storage
  • Plugin ecosystem
  • Custom CSS themes
  • Templates
  • Search and tags

What people use each for

The jobs each tool is most often brought in to do.

Mendeley

  • Storing and organizing large research librariesnot Obsidian
  • Searching and querying PDFs in librarynot Obsidian
  • Uncovering patterns and connections across referencesnot Obsidian
  • Comparing experimental data across multiple studiesnot Obsidian

Obsidian

  • Local-first markdown note taking with no account requirednot Mendeley
  • Linking notes into a personal knowledge graphnot Mendeley
  • Syncing a vault across devices with end-to-end encryption on the paid add-onnot Mendeley
  • Publishing a public site from a vaultnot Mendeley
  • Extending the editor with community pluginsnot Mendeley

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Mendeley

  • Free tier limited to 5 Reading Assistant questions per month and 2GB storage
  • Annual billing required to receive one free month equivalent discount
  • Storage limits restricted on Plus (5GB) and Pro (10GB) tiers

Obsidian

  • Sync is a paid add-on at $4 per month billed annually rather than part of the app
  • Publishing to the web is a further $8 per month per site
  • Commercial use asks for a $50 per user per year licence, though the vendor states it is not required
  • Collaboration is limited compared with a hosted notes tool, since the vault is local files first

Pricing, plan by plan

Mendeley

Free
  • FreeFree
    • 2GB storage
    • 5 Reading Assistant questions per month
  • Plus$4.99/month
    • Unlimited Reading Assistant
    • 5GB storage
    • $55/year annual billing
  • Pro$9.99/month
    • Unlimited Reading Assistant
    • Compare Experiments
    • Ask My Library
  • Max$14.99/month
    • Unlimited Reading Assistant
    • Compare Experiments
    • Ask My Library

Obsidian

Free
  • Obsidian Sync$4/month
    • Sync notes across devices
  • Obsidian Publish$8/month
    • Turn notes into a website

Which should you pick?

Choose Mendeley if

  • You want to start without paying.
Mendeley review

Choose Obsidian if

  • You need bidirectional linking.
  • You want to start without paying.
  • You work on Web, Windows, macOS, Linux, iOS, Android.
  • You also want graph view visualization.
Obsidian review

Questions people ask

Is Mendeley or Obsidian better?
Neither clearly leads. Mendeley starts at Free and Obsidian at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Mendeley or Obsidian?
Mendeley starts at Free and Obsidian at Free.
Does Mendeley or Obsidian run on more platforms?
Mendeley runs on Web. Obsidian runs on Web, Windows, macOS, Linux, iOS, Android.
Can I use Mendeley for free?
Both have a free tier, so you can try either at no cost before committing.
What is Mendeley best used for?
Mendeley is most often used for storing and organizing large research libraries, searching and querying pdfs in library, uncovering patterns and connections across references, comparing experimental data across multiple studies. Of those, storing and organizing large research libraries and searching and querying pdfs in library are not what Obsidian is typically brought in for.
What can Mendeley do that Obsidian cannot?
Obsidian covers Bidirectional linking, Graph view visualization, Markdown support, Local file storage.

Answered from the vendors’ own pages

Mendeley: How much does Mendeley Premium cost?

Mendeley Plus costs $4.99 per month or $55 per year. Pro tier costs $9.99 per month or $110 per year. Max tier costs $14.99 per month or $165 per year. All annual plans include one free month of service.

Source
Obsidian: Is Obsidian free?

Yes. The core Obsidian application is 100% free for personal and commercial use with no limitations. You can use unlimited vaults and every core feature without payment.

Source
Mendeley: Is there a free version of Mendeley?

Yes, Mendeley offers a free tier with 2GB of storage and 5 Reading Assistant questions per month. No credit card is required for the free plan.

Source
Obsidian: What file format does Obsidian use?

Obsidian stores every note as a plain Markdown file. Because it uses standard Markdown instead of a proprietary format, your notes remain portable and can be edited with many other Markdown editors.

Source
Mendeley: What storage do different Mendeley plans include?

The free tier includes 2GB storage. Plus tier provides 5GB storage. Pro tier includes 10GB storage. Max tier offers unlimited storage across all your research libraries.

Source
Obsidian: Can I collaborate with others in Obsidian?

The core application does not include built-in team collaboration features. However, Obsidian offers optional add-ons and can be used with version control systems or cloud storage for collaboration.

Source
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