Castor (Netherlands) and Viedoc (Sweden) are both cloud EDC vendors shortlisted by small and mid-size sponsors and CROs. Their own comparison pages disagree on some points, so this page shows what to verify and adds a lean third option to test free.
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Vendors
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Open items
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What to know first
Why they get compared
Both vendors sell to the same kind of buyer: a small or mid-size sponsor, an academic group or a CRO that wants a configurable system without an enterprise services contract. Castor is often associated with academic and biotech research and, in its own material, emphasises its eCOA breadth and device-study support. Viedoc is often associated with European sponsors and CROs, and in its own material emphasises build speed and a modular suite. Both are vendor claims; use them to form questions.
The independent-looking signal in public review sites is thin and varies by site, so we do not repeat ratings here. The most reliable evidence is a reference call with a customer running a study like yours, and a build of one real visit.
Because each vendor publishes a comparison that favours itself, the safest way to use them is as a list of claims to test. Write each claim down, ask the other vendor to respond in writing, and ask the claiming vendor to demonstrate it in a test study.
Verify
| Topic | Question to ask | Capture, for comparison |
|---|---|---|
| Randomisation and supply | Is it a native module in the same study, or an integration with another system? Who configures it? | Stratified randomisation, blinded roles and kit dispensing are built into the study. |
| eCOA scope | Which outcome types are supported: participant, clinician-reported, observer-reported? Licensed instruments? | Participant questionnaires with licence details on patient forms; site forms are eCRFs. No licence verification. |
| Consent | Is eConsent part of the contracted package and in the same audit trail? | eConsent with email-OTP signatures, investigator countersignature, witness and LAR support. |
| Build | How long from final protocol to a testable study, and who builds it? | You build it; the AI study builder drafts visits and forms from a protocol and nothing saves without review. |
| Data protection | Where is data hosted, who can see identifying data, which sub-processors are used? | EU (Frankfurt) or USA (N. Virginia) chosen at setup; PII segregation; coded IDs for researchers. |
| Specialist studies | Support for device studies, registries or post-market follow-up? | EDC with eCRFs, ePRO and monitoring workflows; see our post-market pages for scope. |
| Exports and exit | Data, dictionary, audit trail and SDTM at lock and at exit? | CSV/Excel with data dictionary; SDTM as SAS XPT with Define-XML. |
| Total cost | All charges over 24 months, including change orders and hosting? | See the pricing page; sandbox is free. |
Capture column is from Capture product pages. Vendor columns are deliberately blank: ask Castor and Viedoc directly.
Vendor responses take weeks. Build your study in the free sandbox meanwhile and see how a self-serve system feels.
Hands-on test
Take one real visit, for example a Week 4 visit with vitals, a lab table and an adverse event, and ask each vendor, or your own team, to build it with an edit check and a calculated field. Count the people involved, the days elapsed and the questions left open. This is a demo-data example of what that visit looks like in Capture.
Systolic BP
VSORRESAbove range: query raised
Diastolic BP
VSORRESMean arterial pressure
Calculated, read-only
117 mmHg CalculatedData protection
European sponsors often shortlist both vendors partly for hosting and GDPR handling. Ask each for the hosting location of your study data, the list of sub-processors, how identifying data is separated from study data, and what support exists for data subject requests. Capture hosts in the EU (Frankfurt) or the USA (N. Virginia), chosen at setup, and separates names from coded IDs at the database layer. See GDPR compliant clinical trial software for what a processor agreement should cover.
Process
Write down every conflicting claim, such as randomisation and eCOA scope, and send each to both vendors.
Same enrolment, sites, modules and two protocol amendments to all vendors, with a request for 24-month pricing.
Have each vendor or your team build one visit with an edit check, and one randomisation and one questionnaire if you need them.
Compare people involved, days elapsed, demonstrated claims, validation and exit answers, and total cost.
Neither wins in general. Both are cloud EDC vendors for small and mid-size sponsors, CROs and academic groups, and their own comparison pages disagree on points such as randomisation and eCOA scope. Test both with the same visit and ask for written answers.
The two vendors describe this differently: one comparison says it needs a third-party integration, while Viedoc's own guide lists a randomisation and supply module. Ask Viedoc to show it in a test study and put the answer in the contract.
Castor's material describes eCOA that includes clinician and observer reported outcomes, while another vendor's page describes Viedoc as mainly participant-reported. Confirm the instrument types you need with both vendors.
We do not state either vendor's pricing because it is not published in a form we can verify. Request quotes for the same enrolment, sites, modules and amendments and compare 24-month totals.
It is quick to test: self-serve, free sandbox, EDC, ePRO, eConsent and randomisation in one audit trail, with EU hosting in Frankfurt. See the single-vendor pages for the detail.
Yes. Capture supports Phase 1 through Phase 3, including SDV per field, blinded roles and multi-site filtering.
Build the same visit in Capture, free. No credit card; you pay only at go-live.