Both are established EDC vendors, but they sit in different tiers: Castor is usually evaluated as a cloud platform for academic and mid-size teams, Rave as an enterprise system for large programmes. This page compares the buying models, not feature lists, and adds a lean third option to test.
Free sandbox · No credit card · 21 CFR Part 11 aligned
| Castor | Medidata Rave | Capture | |
|---|---|---|---|
| Who builds the study | Ask vendor | Ask vendor | Your team, AI-drafted |
| Amendment turnaround and cost | Ask vendor | Ask vendor | Edit and re-approve forms |
| ePRO and eConsent in same study | Ask vendor | Ask vendor | Yes, one audit trail |
| Hands-on trial before contract | Ask vendor | Ask vendor | Free sandbox |
| Priced in writing for your scenario | Request quote | Request quote | Pricing page |
The short version
Two tiers
Vendor and aggregator descriptions of Castor emphasise one platform for EDC, patient-reported outcomes, consent and decentralised-trial workflows, aimed at sponsors, CROs and academic groups. Reviewers on comparison sites say that having these modules together keeps participant data in one place, and also flag that complex endpoint instruments may call for a specialist eCOA provider and that very large enterprises may pair it with separate CTMS or eTMF tools. Those comparison sites label their own assessments as low-to-moderate confidence, so use them to form questions, not conclusions.
Medidata's own fact sheets describe Rave EDC as the foundation of its wider platform, with drag-and-drop eCRF creation in a design tool and a companion product that automates entry of EHR data into Rave. It is widely used by large sponsors and CROs, which means experienced Rave builders and data managers are easy to find. That ecosystem is a genuine advantage for global programmes with many studies in flight.
What neither description tells you is how either behaves for your study: how long a build takes with your team, who must be involved when the protocol is amended, and what the second year costs. Those are the questions below.
Evaluation
Send the same list to every vendor and keep the answers in writing.
| Topic | Question | What Capture offers for comparison |
|---|---|---|
| Build | Who builds our eCRFs and visit schedule, and how long from final protocol to a testable study? | You build it. The AI study builder drafts visits and forms from an uploaded protocol (PDF, DOCX, DOC) and nothing saves without human review. |
| Amendments | What happens when the protocol is amended after go-live, and what does it cost? | Forms move through draft to approved; approved forms are locked for live use. The pricing page lists no change-order line. |
| ePRO and consent | Are participant questionnaires and consent in the same study and audit trail as site data? | EDC, ePRO and eConsent share one study and one audit trail. |
| Data cleaning | How are range checks, queries and SDV configured and who configures them? | Edit checks raise auto-queries when a value breaks a rule; SDV is set per field. |
| Exports | What do we receive at database lock and at exit: data, dictionary, audit trail, SDTM? | CSV/Excel with an automatic data dictionary, audit trail export, and SDTM as SAS XPT with Define-XML. |
| Validation | What validation documentation is supplied to support our own validated use? | Enterprise customers receive documentation to support sponsor validation and UAT; ask for scope. |
| Total cost | What are all charges over 24 months for our enrolment: licence, build, per-study, per-site, change orders, hosting, exit? | Core from $1,000/month with one live study plus $50 per participant per month; see the pricing page for current terms. |
| Exit | In what form do we leave with data, metadata and audit trail, and at what cost? | Exports are available any time; request the same of every vendor in writing. |
Capture rows are from the Capture pricing page and product pages. Vendor columns are deliberately blank: ask Castor and Medidata directly.
Upload your protocol to the free sandbox, review the AI draft, and time how long a testable study takes. No card, no time limit.
Hands-on test
A demo can hide a lot. A better test: take one real visit (for example a Week 4 visit with vitals, a lab table, a diary 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 unresolved. 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 CalculatedCost shape
Even without published prices, you can compare how cost is structured. Ask each vendor whether study build is a service line or self-serve, whether amendments are billed as change orders, whether charges scale by site, participant, module or study, and what is included at go-live and at lock. Software that charges per participant moves with enrolment, while fixed-price services quotes can still move through change orders. See EDC software pricing guide and EDC per-patient pricing explained.
For a small study the dominant costs are often build time and amendments rather than licence. For a large multinational programme, integrations and standardisation across many studies can dominate, and an enterprise ecosystem may repay its overhead. Model your own enrolment with the EDC cost calculator.
Delivery model
Decision aid
Rave is the natural comparator; price a like-for-like scenario.
Test Castor and a lean option such as Capture against the same visit.
Ask for amendment turnaround and price in writing from all three.
Weight self-serve build and sandbox access heavily.
Check site count, support hours and validation documents, then test Capture's Phase 3 controls.
Switching
Moving mid-study is possible but costly; moving between studies is easier. Start new studies on the new platform and let running ones finish, or plan a data migration with a mapped dictionary and a reconciled audit trail. The practical guides are how to switch EDC vendors mid-study, how to migrate from Castor and how to migrate from Medidata Rave.
Single-vendor comparisons are at Capture vs Castor, Capture vs Medidata Rave, Castor EDC alternatives and Medidata Rave alternatives.
Neither wins in general. Rave is built for large programmes with specialist builders; Castor is usually evaluated by academic and mid-size teams that want a cloud platform with EDC, ePRO and consent. The better choice depends on your build model, amendment frequency and budget. Test both with the same visit.
We do not quote either vendor's pricing because it is not published in a form we can verify. Ask both to price the same enrolment, number of sites, modules and amendments, and compare the 24-month total.
Castor describes its platform as combining EDC with eCOA/ePRO and eConsent. Confirm the current modules, and whether your instruments are supported, directly with Castor.
Medidata is a subsidiary of Dassault Systèmes, as its own press releases state.
Because the real alternatives for small and mid-size studies are often neither. Capture is self-serve, has a free sandbox, combines EDC, ePRO, eConsent and randomization in one audit trail, and publishes its pricing, so it is quick to test alongside the others.
Yes. Capture supports Phase 1 through Phase 3, including SDV per field, freeze and lock, blinded roles and multi-site filtering.
Send identical written questions to every vendor, build one real visit with an edit check and a calculated field in each, and compare people involved, elapsed time and 24-month cost.
Keep exploring
Build the same visit in Capture, free. No credit card; you pay only at go-live.