Both are cloud EDC platforms that small biotechs and academic teams shortlist. TrialKit is known for native apps; Castor is usually evaluated as a browser platform with several modules. Here is a neutral way to compare them, plus a lean third option to test free.
Free sandbox · No credit card · 21 CFR Part 11 aligned
| Castor | TrialKit | Capture | |
|---|---|---|---|
| Where data is entered | Ask vendor | Ask vendor | Browser, any device |
| Works without connectivity | Ask vendor | Ask vendor | No offline entry |
| Who builds the study | Ask vendor | Ask vendor | Your team, AI-drafted |
| 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 |
The short version
Two approaches
Vendor and aggregator descriptions of Castor emphasise one platform for data capture, participant-reported outcomes and consent, with a no-code study builder aimed at sponsors, CROs and academic groups. Comparison sites that rank it tend to praise how approachable it is for non-programmers and note that very complex endpoint instruments or large enterprise tooling needs may call for specialist add-ons. Treat those as questions to ask, not findings.
Crucial Data Solutions presents TrialKit as an app-centred system. Its own material describes native apps for iPhone, iPad, Android and Mac, a 2017 launch of building and running studies on a mobile device, and later features such as a hand-off mode for participant surveys and form layouts targeted to specific devices. Its brochure says EDC works across browser and app, while an eSource module is mobile only. Public material we found did not describe offline capture either way, so that remains a question for the vendor.
Put simply: one is usually bought for the builder and the module set, the other for the device experience. Your sites and participants decide which matters more.
Evaluation
Send the same list to every vendor and keep the answers in writing.
| Topic | Question | What Capture offers for comparison |
|---|---|---|
| Devices | Which devices and operating systems are supported for site staff and for participants, and is an app required? | Browser on phones, tablets and desktops. No app to install; participants open questionnaires from a secure link. |
| Connectivity | What happens when a site has no signal: is data held on the device, and how does it sync and resolve conflicts? | Offline data entry is not offered. Sites and participants need a connection. |
| Build | Who builds the 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); nothing saves without review. |
| 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? | Edit checks raise auto-queries when a value breaks a rule; SDV is set per field. |
| Exports | What do we receive at lock and at exit: data, dictionary, audit trail, SDTM? | CSV/Excel with an automatic data dictionary, and SDTM as SAS XPT with Define-XML. |
| Validation | What validation documentation supports our own validated use? | Enterprise customers receive documentation to support sponsor validation and UAT; ask for scope. |
| Total cost | All charges over 24 months for our enrolment: licence, build, per-study, per-site, change orders, hosting, exit? | See the pricing page for current terms; the sandbox is free. |
Capture rows come from Capture product pages. Vendor columns are deliberately blank: ask Castor and TrialKit directly.
Upload your protocol to the free sandbox, review the AI draft, and open the questionnaire on a phone and a tablet. No card, no time limit.
Hands-on test
A demo on a laptop proves little for a study run on tablets. Take one real visit, ask each vendor for a test study, and have a coordinator enter it on the actual device, in the actual room, on the actual network. Record taps, errors and what happens when the connection drops. This is a demo-data example of a short diary a participant completes on a phone in Capture.
Daily symptom diary
Subject 001-0042 · Day 12 (demo data)
Pain right now
PAINSlept well last night
SLEEPTook study medication
ADHERDevice model
Cost shape
Without published prices you can still compare how cost is structured. Ask each vendor whether study build is a service or self-serve, whether amendments are billed separately, whether charges scale by study, site, participant or module, and what is included at go-live and lock. See the EDC software pricing guide and model your own enrolment with the EDC cost calculator.
For a small study the dominant costs are often build time and amendments rather than licence. For a distributed field study, device logistics may dominate instead. Count both.
Decision aid
Test offline behaviour with TrialKit and Castor on real devices; Capture needs a connection.
A browser platform such as Castor or Capture is simpler; compare the builders.
Ask all three for the module list in the contract, not the roadmap.
Ask for amendment turnaround and price in writing from all three.
Weight self-serve build and sandbox access heavily.
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. Practical guides: how to switch EDC vendors mid-study, how to migrate from Castor and how to migrate from TrialKit.
Single-vendor views are at Capture vs Castor, Capture vs TrialKit, Castor EDC alternatives and TrialKit alternatives.
Neither wins in general. TrialKit is known for native apps; Castor is usually evaluated as a browser platform with several modules. The better choice depends on where data is entered, the module set you need and your budget. Test both with the same visit.
We could not confirm offline behaviour from public material. TrialKit describes native apps and browser access; ask the vendor in writing how data is held and synced when there is no signal, and test it.
Castor describes its platform as combining EDC with eCOA/ePRO and eConsent. Confirm the current modules and your instrument types directly with Castor.
We do not state either vendor's pricing because it is not published in a form we can verify. Ask both to price the same enrolment, sites, modules and amendments and compare 24-month totals.
Because it is quick to test alongside the others: self-serve, free sandbox, EDC, ePRO, eConsent and randomisation in one audit trail. It runs in the browser and does not offer offline entry, so it fits online sites.
Yes. Capture supports Phase 1 through Phase 3, including SDV per field, blinded roles and multi-site filtering.
Send identical written questions to every vendor, build one real visit with an edit check in each, test on the devices your sites use, and compare people involved, elapsed time and 24-month cost.
Build the same visit in Capture, free. No credit card; you pay only at go-live.