Now in early access

Your viva is spoken. Your practice should be too.

Defensia lets PhD candidates rehearse a real-time mock viva with an AI examiner that asks questions grounded in their own thesis.

No credit card required. Currently for UK university students — sign up with your .ac.uk email.

60 min

free to start, no card needed

6

distinct examiner personalities

5 categories

of AI-scored feedback per session

Privacy & security

Say it out loud. Nothing is ever recorded.

A viva is stressful enough without wondering what happens to what you say.

No voice recordings

Audio is processed live to run the session — it is never recorded or saved.

Encrypted throughout

Your thesis and session transcripts are encrypted in transit and at rest.

Delete it any time

One click removes a thesis and every transcript, session, and feedback record tied to it.

Full details in our Privacy Policy.

How it works

From thesis upload to confident viva — in three steps.

01

Upload your thesis

Upload your thesis PDF and we index the full text. Every question in your sessions will be grounded in your specific work — your methodology, your findings, your arguments.

02

Choose an examiner

Select from six AI examiner personalities. Start supportive to build confidence, then work up to the devil's advocate before the real thing.

03

Practise out loud

Run a live audio session. Speak your answers. When you're done, review scored feedback across five categories and track improvement over time.

Built for the viva, not for general chat

Every design decision is about making your practice as realistic and useful as possible.

Questions from your actual thesis

The AI reads and indexes your document in full. Every question is generated from your specific work — not generic PhD prompts that could apply to anyone.

Speak your answers out loud

The real viva is spoken, not typed. Practise with live audio to build the clarity and confidence that only comes from saying it out loud.

Scored feedback after every session

Category breakdowns across research contribution, methodology, literature, critical thinking, and presentation. Track how you improve across sessions.

A real-time mock viva, not a quiz

Question, spoken answer, follow-up, feedback — all grounded in your thesis.

Methodologist

Examiner speaking

Live session
E

EXAMINER

"Your methodology chapter describes a thematic analysis approach. Can you explain why you chose inductive coding rather than applying an existing theoretical framework to your data?"

YOUR ANSWER

"I chose inductive coding because my research question was exploratory — I was examining patterns in participant experience that hadn't been categorised before, so applying a predetermined framework would have constrained the analysis…"

E

FOLLOW-UP

"How did you establish rigour in that process? Did you use member checking or inter-rater reliability measures?"

SESSION FEEDBACK

Methodology
82
Contribution
88
Critical thinking
74
Presentation
79

Choose your examiner

Six AI examiner personalities. Practise the one you expect — or the one you fear most.

Supportive

Builds confidence while probing your understanding. Constructive feedback, not harsh criticism. Ideal for early-stage practice.

Challenging

Demands rigorous justification for every claim. Doesn't let weak arguments slide. Prepares you for examiners who push hard.

Methodologist

Deep focus on research design, validity, reliability, and statistical choices. Methodological rigour is everything.

Interdisciplinary

Brings perspectives from adjacent fields and challenges disciplinary assumptions. Useful if your work crosses boundaries.

Devil's Advocate

Takes the opposing view on everything. Forces you to defend every position under genuine intellectual pressure.

Socratic

Uses deep questioning to surface gaps in your reasoning you didn't know were there. Expect follow-up on every answer.

Simple pricing

Start free. One pass covers most students. No subscription.

Free trial

60 min

included on sign-up

  • Full access to all features
  • All 6 examiner personalities
  • Live audio sessions
  • Scored feedback
  • No credit card required

Viva Pass

£49 one-time

after your free trial

  • Everything in the free trial
  • 240 minutes of practice
  • No monthly subscription
  • Credits never expire

Common questions

The viva is the most important hour of your PhD. Prepare for it.

Your first 60 minutes are free. No credit card, no commitment — just practice.