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Research · head to head

Aurelius vs Castor EDC

Aurelius logo

Aurelius

Research

UX research repository for tagging notes, building insights and finding them again years later

From
$49/month
Rated
-
Full reviewWebsite
Castor EDC logo

Castor EDC

Research

Electronic data capture and eConsent for clinical trials, built for investigator-initiated studies as well as sponsors

From
On request
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Aurelius aurelius does not recruit participants or run unmoderated studies, so it is always a second tool alongside a testing or recruitment platform and never the whole research budget.; Castor EDC nothing is published: pricing is quoted only after a scoping call and protocol review, so budgeting a grant application means asking for a quote months before the study is funded and hoping the scope holds.
  • They diverge on capability: Aurelius covers Research repository, Castor EDC covers Browser-based study build.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Aurelius and Castor EDC actually diverge.

Attributes where Aurelius and Castor EDC differ
AttributeAureliusCastor EDC
Starting price$49/monthOn request
Pricing modelFlat monthly fee, unlimited usersquote
PlatformsWebWeb, iOS, Android

Identical on both: free tier (No), 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 Aurelius

  • Research repository
  • Analysis board
  • Tagging
  • Insights and recommendations
  • Transcription
  • AI assist
  • Automatic report builder
  • Universal search

Only in Castor EDC

  • Browser-based study build
  • 21 CFR Part 11 workflows
  • eConsent
  • ePRO and surveys
  • Randomisation
  • Per-study licensing
  • Grant-funded pricing paths
  • Data export

What people use each for

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

Aurelius

  • A research team of three whose findings currently live in individual Miro boards and Google Docs that nobody outside the team can find six months laternot Castor EDC
  • A product organisation that wants every designer and product manager to search past research without paying forty repository seatsnot Castor EDC
  • A consultancy running discovery for multiple clients that needs tagged evidence kept separate per client but searchable internallynot Castor EDC
  • A team preparing a repeat study who need to know what was already learned about the same problem two years ago before they recruit anyonenot Castor EDC

Castor EDC

  • An academic hospital running an investigator-initiated trial that cannot fund a sponsor-grade EDC contract or a data management CROnot Aurelius
  • A medical device company collecting post-market clinical follow-up data with Part 11 audit trailsnot Aurelius
  • A multi-site registry that needs remote eConsent because participants are recruited nationally rather than at a clinicnot Aurelius
  • A biotech running a small phase two study that wants the database built by its own clinical team in weeks rather than commissionednot Aurelius

Where each one falls short

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

Aurelius

  • Aurelius does not recruit participants or run unmoderated studies, so it is always a second tool alongside a testing or recruitment platform and never the whole research budget.
  • Integrations are thin, with Zapier, Jira and Slack rather than direct connections to the call recording and testing tools most teams already run, so getting material in often means manual upload.
  • The tag vocabulary is only as good as the discipline applied to it, and repositories where several researchers invent overlapping tags become unsearchable within a year with no built-in governance to prevent it.
  • Unlimited users is genuinely unlimited but permissions are basic below Enterprise, so a team that needs client-safe or stakeholder-only views has to buy the quoted tier for something that reads as a table-stakes control.
  • It is a small independent vendor competing with much better funded repositories, which is a real procurement risk for an organisation storing years of research in it, and enterprise assurance material such as penetration test reports sits behind the top tier.

Castor EDC

  • Nothing is published: pricing is quoted only after a scoping call and protocol review, so budgeting a grant application means asking for a quote months before the study is funded and hoping the scope holds.
  • Price scales on protocol complexity rather than a simple unit, so two studies with the same participant count can be quoted very differently and there is no public benchmark to argue against.
  • Modules such as eConsent, ePRO and randomisation are quoted on top of the base platform, so the headline EDC figure is rarely the number that appears on the final proposal.
  • It is deliberately lighter than the full sponsor suites, so a study that grows into a global registrational programme needing integrated CTMS, safety, IRT and full trial supply management will need additional systems and the interfaces between them.
  • Regulatory responsibility does not transfer with the software: the platform supports Part 11 compliant workflows, but system validation for your intended use, SOPs and audit readiness remain your obligation and your cost, which sponsors new to EDC consistently underestimate.

Pricing, plan by plan

Aurelius

$49/month
  • Professional$49/month
    • Unlimited users
    • Unlimited projects and storage
    • Notes, tags and documents
  • Premium$199/month
    • Everything in Professional
    • Recommendations
    • Universal search across projects
  • Enterprise$undefined/year
    • Everything in Premium
    • SSO with SAML 2.0
    • IP allowlisting

Castor EDC

On request
  • Castor EDC$undefined/year
    • Priced per study on protocol complexity, duration, sites and modules
    • 21 CFR Part 11 and ICH GCP workflows
    • eConsent, ePRO and randomisation modules quoted separately

Which should you pick?

Choose Aurelius if

  • You need research repository.
  • You also want analysis board.
Aurelius review

Choose Castor EDC if

  • You need browser-based study build.
  • You work on Web, iOS, Android.
  • You also want 21 cfr part 11 workflows.
Castor EDC review

Questions people ask

Is Aurelius or Castor EDC better?
Neither clearly leads. Aurelius starts at $49/month and Castor EDC at On request, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Aurelius or Castor EDC?
Aurelius starts at $49/month and Castor EDC at On request.
Does Aurelius or Castor EDC run on more platforms?
Aurelius runs on Web. Castor EDC runs on Web, iOS, Android.
What is Aurelius best used for?
Aurelius is most often used for a research team of three whose findings currently live in individual miro boards and google docs that nobody outside the team can find six months later, a product organisation that wants every designer and product manager to search past research without paying forty repository seats, a consultancy running discovery for multiple clients that needs tagged evidence kept separate per client but searchable internally, a team preparing a repeat study who need to know what was already learned about the same problem two years ago before they recruit anyone. Of those, a research team of three whose findings currently live in individual miro boards and google docs that nobody outside the team can find six months later and a product organisation that wants every designer and product manager to search past research without paying forty repository seats are not what Castor EDC is typically brought in for.
What can Aurelius do that Castor EDC cannot?
Aurelius covers Research repository, Analysis board, Tagging, Insights and recommendations. Castor EDC covers Browser-based study build, 21 CFR Part 11 workflows, eConsent, ePRO and surveys.

Answered from the vendors’ own pages

Aurelius: Does the price really include unlimited users?

Yes. Professional at 49 US dollars a month and Premium at 199, both billed yearly, both with unlimited users, projects and storage.

Castor EDC: Is there a free academic version?

No published free tier. There are academic, non-profit and grant-funded pricing paths, but each is quoted rather than self-service.

Aurelius: Can I run usability tests in it?

No. Aurelius stores and analyses research; it does not recruit participants or host sessions. Pair it with a testing tool.

Castor EDC: Is it 21 CFR Part 11 compliant?

It supports Part 11 compliant workflows with audit trails and electronic signatures. Validating the system for your specific use remains your responsibility.

Aurelius: What is the difference between Professional and Premium?

Premium adds universal cross-project search, collections, recommendations and Zapier. If your value comes from finding old research, Premium is the tier that delivers it.

Castor EDC: Do I need a programmer to build a study?

No. Case report forms are configured in the browser, which is the main reason academic groups adopt it.

Aurelius: Is there single sign-on?

Only on Enterprise, along with IP allowlisting, Jira and advanced permissions. Everything below is quoted separately.

Castor EDC: How long does a quote take?

Castor states a full pricing proposal within five business days of sharing the protocol.

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