Replio AI Tutor

AI voice tutor apps compared

Replio next to Notilo, iTutor, Knowt, Khanmigo and ChatGPT Voice: which ones hold a real spoken conversation, which ones learn from your own notes, and what each gives you for free.

Get Replio on Google Play Discover the app

Searching for an AI voice tutor returns two very different kinds of product: study apps that turn your material into quizzes and let you talk about it, and general assistants with a voice mode. This page compares five tools students actually use with Replio, on the criteria that decide whether you learn: does it work from your own course, does the voice hold a real conversation, and does it make you come back. Lyah AI, which appears for the same searches, sells voice tutors to teachers and institutions rather than to students, so it is not in the table.

Facts about other apps come from their public websites, checked in September 2026. Features, limits and free tiers change often, so verify on each site before choosing. Replio has no affiliation with any of them.

Side by side

Criterion	Replio	Notilo	iTutor	Knowt	Khanmigo	ChatGPT Voice
Voice conversation	Live spoken dialogue with one tutor character you create. You can interrupt at any moment; a transcript is kept.	Voice tutor with instant spoken responses, per its site.	Voice tutoring conversations, included in the free tier, per its site.	Kai can quiz you out loud and turn uploads into a podcast, per its site.	Text chat first: a guided, question-led tutor rather than an open spoken conversation.	Live spoken conversation with a general assistant.
Works from your own notes	Yes. Photograph your notes or upload a PDF or Word file; the tutor teaches from that material only.	Yes: notes, PDFs and YouTube videos can be uploaded; materials are optional.	Yes: PDFs, notes, slides and photos of homework, with answers grounded in that material.	Yes: lecture recordings, PDFs, slides and handwritten notes.	Built around Khan Academy's content library; uploading your own notes is not presented on its site.	Files can be uploaded in text chat; the voice conversation is open-ended and not tied to a course.
Course plan by chapter	Yes. The app reads your material's structure and turns it into an ordered plan; one session covers one chapter.	Not stated on its site.	Study plans generated from your uploads, per its site.	Not stated on its site.	Khan Academy's courses and units.	No plan; every conversation starts blank.
Quizzes and spaced repetition	Yes. A question bank generated chapter by chapter, with spaced repetition so missed questions come back sooner.	Practice questions generated from your documents; spaced repetition not stated.	Auto-generated quizzes and flashcards with instant scoring; spaced repetition not stated.	Yes: flashcards, practice tests and spaced repetition are core features.	Khan Academy practice exercises; spaced repetition not stated.	No quiz bank or spaced repetition; you can ask it to quiz you in the moment.
Homework help from a photo	Yes. Photograph an exercise and the tutor gives hints, not the answer.	Not stated on its site.	Yes: photos of homework can be uploaded.	Not stated on its site.	Step-by-step guidance that leads you to the answer rather than giving it.	Can read a photo and usually gives the answer.
Languages	10 app languages; the tutor speaks the language you study in.	Not stated on its site.	12 languages, per its site.	Not stated on its site.	Not stated on its site.	Many languages.
Platforms	Android app on Google Play; an iPhone version is on its way.	Web app, per its site.	Web-based, per its site.	iOS, Android and web.	Khan Academy web and apps.	iOS, Android and web.
Free tier	One subject, quizzes from your own notes and a trial of tutor minutes, free. Subscriptions add minutes and subjects.	Free plan with daily limits on AI words and documents, then premium plans, per its pricing page.	Free for individual students, per its site; team plans for schools and companies.	Core features free, with paid student plans, per its site.	Paid subscription for learners; free for eligible teachers. Learner accounts require a US billing address, per its site.	Free tier with daily limits on voice, per OpenAI's help center.
Where your data is processed	On Replio's European platform; conversation history can be deleted from the app.	Not stated on its site.	Not stated on its site.	Not stated on its site.	US organization; details in its privacy policy.	US organization; details in OpenAI's privacy policy.

App by app

Notilo

Web study assistant with a voice tutor, document chat and YouTube-to-notes notilo.ai

Where Notilo shines

Notilo bundles a lot into one workspace: document chat, YouTube video summaries, flashcards, citations and a voice tutor, all in the browser. If you study from lecture videos as much as from notes, that reach is useful.

How Replio differs

Replio is a phone app built around one thing, the spoken session on your own chapters, with a course plan and quizzes that make you come back. Notilo's voice tutor is one feature among many in a web workspace.

iTutor

Free web platform that turns uploads into flashcards, quizzes, exam simulators and voice tutoring itutor.study

Where iTutor shines

iTutor is hard to beat on price: its site presents the individual plan as free forever, voice included, with a wide toolset from mind maps to exam simulators and 12 interface languages.

How Replio differs

Replio pins everything on the phone and the voice: a native Android app, one tutor character with a name and a voice you chose, sessions that follow your chapters in order, and quizzes on a spaced schedule.

Knowt

Flashcards and notes app whose AI, Kai, can quiz you out loud knowt.com

Where Knowt shines

Knowt is a mature flashcard app first, with a free unlimited learn mode, practice tests, matching games and native apps on both phone platforms. Its lecture recording upload is a real differentiator for students who learn in lecture halls.

How Replio differs

Knowt's voice is a quiz-out-loud and podcast feature on top of flashcards. Replio starts from the conversation: an open, interruptible dialogue with a tutor who explains, questions and corrects, chapter by chapter.

Khanmigo

Khan Academy's Socratic AI tutor, built around its own course library khanmigo.ai

Where Khanmigo shines

Khanmigo sits on top of the most complete free course library there is, and its Socratic style is deliberately built to make you think rather than to hand over answers. For math and science inside Khan Academy's curriculum, that is a strong fit.

How Replio differs

Replio is not a course library: it is a tutor for your course, the one your teacher gives, in the language you study in, on your phone, with your voice. Khanmigo learner accounts also require a US billing address, per its site.

ChatGPT Voice

General assistant with a live voice mode, not a study app chatgpt.com

Where ChatGPT Voice shines

ChatGPT Voice is the most natural general conversation available for free, in almost any language, on every device. For a quick explanation of a concept, it is excellent.

How Replio differs

It does not know your course, does not keep a plan and does not come back to what you missed. Replio's tutor is built from your chapters, quizzes you on them and tracks each one until it is solid.

How to choose an AI voice tutor

Conversation or read-aloud?

Some tools speak their text answers; a real voice tutor listens, lets you interrupt and adapts. Test it with a question halfway through an explanation.

Your course or the internet?

A tutor that has read your notes uses your teacher's terms and your exam scope. A general assistant fills the gaps with whatever it knows.

Does it bring you back?

One good session is not a study routine. Look for a plan with an end, chapters marked solid, and quizzes that resurface what you missed.

Which one for you

Pick another tool if

You study mostly from lecture videos or recordings and want them summarized (Notilo, Knowt).
You follow Khan Academy's curriculum and live in the US (Khanmigo).
You want a free general assistant for quick explanations in any language (ChatGPT Voice, iTutor).

Pick Replio if

You want to talk through your own chapters with a tutor that only knows your material.
You want a plan and a quiz routine that carry you to exam day, not a one-off chat.
You are on Android, study in one of 10 languages, and want your notes processed in Europe.

Questions about AI voice tutors

What is an AI voice tutor?

An app you study with by speaking. You ask, explain and answer out loud; the tutor listens, replies with its voice and corrects you. The good ones work from your own material and keep a plan, instead of answering from general knowledge.

Is a voice tutor better than flashcards?

They do different jobs. Flashcards drill recall; a conversation shows whether you can explain and connect ideas, which is what oral exams and essays test. Replio does both: spoken sessions and quizzes with spaced repetition from the same notes.

Which AI voice tutor apps are free?

Per their sites: iTutor presents its individual plan as free, Notilo and Knowt offer free plans with limits, ChatGPT Voice has a free tier with daily voice limits, and Khanmigo is a paid subscription for learners. Replio is free to start with one subject, quizzes and a trial of tutor minutes.

Can I use Replio for a language I am learning?

Yes. Create a language subject and the tutor holds the conversation in that language at your level. It runs on the same engine companies use to train their teams.

Try the tutor on your own notes

Free to start on Google Play: one subject, quizzes and a trial of tutor minutes.

Get it on Google Play