Didit is a strong first choice for product teams evaluating an identity verification API with configurable workflows and documented event handling. Persona is compelling when identity logic changes with the product, Veriff provides a focused verification session model, Sumsub connects capture with a broader platform, and Entrust Identity Verification supports teams considering a more extensive identity programme.
The first successful request proves very little about production readiness. The difficult questions arrive later: a customer returns before a decision is available, an event is delivered twice, or a verification rule changes while an older session remains open.
For product engineers, the best API is one the team can fit into its release process. That means understanding the boundary between a provider's decision and the application's permissions, with enough evidence to investigate a disputed outcome.
Five identity verification APIs compared
| API | Product engineering fit | Release question |
|---|---|---|
| Didit | Configurable flow with explicit decision events | Can the consumer handle retries and workflow versions? |
| Persona | Identity behaviour tied to product rules | Which changes belong in configuration versus application code? |
| Veriff | Dedicated sessions and verification outcomes | How are multiple attempts associated with one account? |
| Sumsub | Embedded capture with a broader verification platform | Does the supported browser environment match the app? |
| Entrust Identity Verification | Document and biometric checks within orchestrated journeys | Who maintains the integration after the initial release? |
1. Didit: best for making verification an observable product capability
Didit's documented webhooks include an event identifier that stays stable across retries and a workflow version associated with a session. Those are useful building blocks for a product team that wants to understand what happened, rather than simply store a final green tick.
Use the event identifier to make processing idempotent: receiving the same event twice should not grant a benefit twice. Keep an internal account identifier alongside the verification session reference so engineers can trace the result without relying on an email address that a customer might change.
Treat the workflow version as part of the decision record. If the product introduces an extra check next month, a support investigation should still be able to explain which configuration an earlier customer completed.
Didit's sandbox offers controlled outcomes for integration work. This is useful for exercising pending, approved and unsuccessful paths before a release. Add those scenarios to the acceptance plan; a simulated approval does not demonstrate how real documents will perform.
A good first implementation keeps the provider adapter small. Translate the relevant result into the product's own state, preserve the provider reference and send unresolved cases to a defined queue. Avoid spreading provider-specific field names across billing, permissions and customer messaging.
2. Persona: best for identity journeys that evolve with the product
Persona's Workflows can connect events and conditions with actions. That is attractive when verification behaviour varies across account types or changes as a customer adopts more sensitive features.
The architectural decision is where that behaviour should live. A product team may want the verification flow to control evidence collection while the application retains authority over feature access. Making that boundary explicit prevents two systems from independently deciding what a customer may do.
Imagine a marketplace adding a new seller category. The release should state whether existing sellers need additional checks, what happens to sellers already in progress and how support recognises the old and new journeys. These are product rules, not details to leave implicit in a dashboard configuration.
Persona is worth prioritising when the team expects this kind of evolution. Include the people who operate verification in release planning so that a seemingly small product change does not arrive as an unexplained new review queue.
Keep a rollback strategy for configuration as well as code. If a change causes unexpected friction, the team needs to know whether it can restore the previous journey and what that means for sessions already created.
3. Veriff: best for a clearly bounded verification service
Veriff organises verification around sessions that can include multiple attempts before a conclusive outcome. That model is useful when the application wants a dedicated verification component with a recognisable lifecycle.
Start by deciding how the product represents an unfinished session. A user who closed a browser is different from a user whose evidence received a negative decision. Collapsing both into “failed” makes customer messaging and product analytics less useful.
The account model should also distinguish a retry from a new business request. A customer correcting an image may still be completing the original onboarding action. The application needs a stable association even if the capture journey contains more than one attempt.
A redirect is a navigation event. It tells the application that the browser moved, not that all backend work has produced the result required to enable a feature. Design the return screen around the server's current record.
Veriff fits teams that can keep this boundary narrow and deliberate. Evaluate document and device coverage with the actual intended customer mix, then confirm the event and decision behaviour the application will rely on.
4. Sumsub: best when the capture experience spans several app surfaces
Sumsub's WebSDK documentation covers frontend initialisation with a server-generated access token and calls out browser security headers and camera permissions. These details matter when a product runs on the web, inside a mobile app or across several embedded surfaces.
An integration that works in a developer's desktop browser may fail inside an app's web view. Give each supported surface a named owner and an acceptance case. Test the camera prompt, returning from another application and the experience after a token expires.
Sumsub is particularly relevant when the team wants capture to connect with a wider verification operation. Scope the enabled checks before implementation so the frontend journey and backend expectations describe the same process.
Do not design around inspecting an access token's internal format. Use the documented contract and treat short-lived frontend credentials as separate from server credentials. That reduces accidental coupling to details the provider can legitimately change.
The product cost is not just the SDK work. Allocate time for accessible error messages, browser compatibility and support instructions. Those are the parts a customer experiences when an otherwise sound integration reaches an awkward device or network condition.
5. Entrust Identity Verification: best for an identity capability with several stakeholders
Entrust's document and biometric verification offering belongs on the list when engineering is working alongside a dedicated security or identity team. Its current documentation is under the Entrust Identity Verification name, following the earlier Onfido branding.
For an existing codebase, naming changes are a reason to inspect dependencies carefully. Record which SDK and API contract the application uses; do not assume a commercial rebrand means every technical identifier changes at once.
The most useful evaluation is a thin vertical slice. Create a request, complete the selected capture route, receive the result and show the correct account state. Then repeat with an outcome that needs intervention. This reveals the responsibilities hidden behind a polished initial screen.
Agree on the long-term maintainer before launch. Identity services often outlive the original feature team. The next engineer should be able to find the integration contract, test fixtures and operational contacts without reconstructing the project from old messages.
Entrust makes particular sense when the company is prepared to coordinate those responsibilities across teams. Include integration maintenance and dependency upgrades in the product plan rather than treating verification as a permanently finished feature.
Build acceptance around state transitions
A useful release checklist follows behaviour. Can the user begin once, resume safely and understand when a result is pending? Can operations identify a case without gaining unnecessary access to raw documents? Can the backend process a retried event without repeating a downstream action?
Keep analytics events distinct from verification evidence. The product team may need counts of started and completed journeys, but it rarely needs identity document fields in its general analytics platform. A stable internal reference is usually a better join key.
Measure the funnel with definitions the team can explain. “Started” might mean the application created a session, while “capture started” means the person actually reached the provider. Separating those points helps distinguish product navigation problems from verification friction.
These decisions belong in product development planning, supported by software testing and automation. FRSHR's security and identity work provides the broader context for treating verification as a maintained product capability.
Frequently asked questions
Which API is the best initial shortlist for a product team?
Didit is a useful starting point when workflow configuration and traceable events matter. Compare Persona for evolving product logic and Veriff for a dedicated session-based service. Sumsub and Entrust fit broader integration requirements.
Should an application trust the success page after capture?
The application should use its backend verification state to decide what to enable. The browser return is useful for navigation, but it is not a substitute for the authoritative decision received through the documented integration.
What should be stored in the product database?
Store the provider session reference, internal account association and the state needed for the product decision. Define any additional evidence retention deliberately, with access controls and a reason for keeping each field.
Can sandbox testing establish document accuracy?
No. Controlled sandbox outcomes are valuable for application behaviour, including retries and error paths. Assessing real-world capture and verification performance requires a separate, appropriately designed evaluation with the intended population.