Plain-English explainer

AI models explained (for students)

ChatGPT, Gemini, Claude, Microsoft Copilot, Perplexity, and Grok are all AI assistants with free tiers. They differ in their built-in features (study modes, source links, Office or Google integration), their paid plans and student offers, and how they handle your data. Several may use your chats for training unless you switch it off. Open models run through Ollama or LM Studio can work entirely on your own computer. Everything below comes from each company’s official pages, checked 2026-10-18.

We describe documented features, not rankings. The right one is whichever fits your task and your course rules. See Which AI should I use?

At a glance

Assistant	Free tier	Paid from	Student offer	Training on your chats	Checked
ChatGPT OpenAI	Unlimited everyday text chats (subject to abuse guardrails), with limited uploads, image creation, deep research, and memory. Free input max is about 12 pages for GPT Instant.	Go $8/mo (U.S.) · Plus $20/mo · Pro plans cost more	4 free months of Plus for eligible U.S. college & grad students (claim by Oct 31, 2026; card required; then $20/mo)	May be used unless you opt out	Last checked: 2026-10-18 Source Source 2
Gemini Google	Free plan with a Google Account (Flash-Lite model). Usage limits are compute-based and refresh every 5 hours until you hit a weekly limit.	Google AI Plus $4.99/mo · Google AI Pro $19.99/mo · Ultra from $99.99/mo	Google AI Pro free for 1 year for eligible U.S. college students 18+ (redeem by Dec 31, 2026; card required; then $19.99/mo)	Set by Keep Activity; off = not used	Last checked: 2026-10-18 Source Source 2
Claude Anthropic	Free for everyone. Usage limits apply (no numbers published).	Pro $17/mo billed annually ($200 up front), or $20 monthly · Max from $100/mo	None published for individuals (check site)	Only if model improvement is on (listed as opt-out)	Last checked: 2026-10-18 Source Source 2
Microsoft Copilot Microsoft	The Copilot app is free, with limited chat, image creation, and uploads (numeric limits not published).	Microsoft 365 Personal $9.99/mo or $99.99/yr (AI usage limits apply)	50% off Microsoft 365 Personal for verified college students (exact price: check site)	Used unless you opt out (exceptions)	Last checked: 2026-10-18 Source Source 2
Perplexity Perplexity	Free, with limited Pro Searches.	Pro $17/mo billed annually	Education Pro $10/mo for verified students (SheerID)	On by default; opt out	Last checked: 2026-10-18 Source Source 2
Grok SpaceXSI (x.ai)	Free, with limited chat requests and image generation.	Plus $8/mo · Premium $30/mo · Super $100/mo · Ultra $200/mo	None published (check site)	May be used unless you opt out	Last checked: 2026-10-18 Source Source 2
Open & local models (Ollama, LM Studio) Various model makers	Free to run locally. Ollama: “Running models on your own hardware is always unlimited.” LM Studio Free runs local models.	Optional cloud: Ollama Pro $20/mo ($200/yr) · LM Studio Bionic+ $20/mo	None published	Local: stays on your device	Last checked: 2026-10-18 Source Source 2

One by one

ChatGPT

OpenAI

A general-purpose AI assistant for chat, files, images, voice, and coding.

For school: Study mode (on every plan, including Free) quizzes you and guides you step by step instead of giving answers. Deep research, file uploads, data analysis, and Projects. Plus adds scheduled tasks and higher limits.
Free tier: Unlimited everyday text chats (subject to abuse guardrails), with limited uploads, image creation, deep research, and memory. Free input max is about 12 pages for GPT Instant.
Paid: Go $8/mo (U.S.) · Plus $20/mo · Pro plans cost more
Student offer: 4 free months of Plus for eligible U.S. college & grad students (claim by Oct 31, 2026; card required; then $20/mo)
Training: On Free, Go, Plus, and Pro, OpenAI may use your chats to train its models. To opt out: Settings → Data controls → turn off “Improve the model for everyone.” Temporary chats aren’t used for training. If you give thumbs up or down feedback, that whole conversation may be used even if you opted out.
Retention: Deleted chats are scheduled for permanent deletion within 30 days (with some security and legal exceptions). Temporary chats may be kept up to 30 days for safety.
Last checked: 2026-10-18 · source 1 · source 2 · source 3 · source 4 · source 5 · source 6 · source 7

Gemini

Google

Google’s AI assistant, plus Gemini Notebook (formerly NotebookLM) for working from your own sources.

For school: Google’s student page lists study notebooks, personalized quizzes from your notes, step-by-step explanations, and rubric-based feedback. The Free plan includes Deep Research, Canvas, image generation, and Gemini Notebook.
Free tier: Free plan with a Google Account (Flash-Lite model). Usage limits are compute-based and refresh every 5 hours until you hit a weekly limit.
Paid: Google AI Plus $4.99/mo · Google AI Pro $19.99/mo · Ultra from $99.99/mo
Student offer: Google AI Pro free for 1 year for eligible U.S. college students 18+ (redeem by Dec 31, 2026; card required; then $19.99/mo)
Training: Controlled by the Keep Activity setting. If Keep Activity is off and you don’t send feedback, Google doesn’t use your future chats to improve its AI models. Temporary chats aren’t used for training. Even with it off, Google uses chats to respond and for safety, including with human reviewers.
Retention: Activity auto-deletes after 18 months by default; you can change that to 3 or 36 months, or never. Chats with Keep Activity off (and temporary chats) are kept 72 hours. Chats reviewed by humans are kept up to 3 years, even if you delete your activity.
Last checked: 2026-10-18 · source 1 · source 2 · source 3 · source 4

Claude

Anthropic

An AI assistant for chat, documents, code, and creating files.

For school: The Free plan includes web search, Artifacts, file creation with code execution, Claude Slides and Docs, and up to 5 Projects. Pro adds Research, Claude Code, and more usage. Context window up to 1M tokens, varying by model.
Free tier: Free for everyone. Usage limits apply (no numbers published).
Paid: Pro $17/mo billed annually ($200 up front), or $20 monthly · Max from $100/mo
Student offer: None published for individuals (check site)
Training: Anthropic uses consumer chats for training if you allow it in your Privacy Settings (model improvement), if a chat is flagged for safety review, or if you otherwise opt in. Its pricing page lists model training as “opt-out” on Free and Pro, so check your setting. Incognito chats aren’t used for training.
Retention: Deleted chats are removed from your history immediately and from back-end storage within 30 days. If you allow training, data may be kept de-identified for up to 5 years.
Last checked: 2026-10-18 · source 1 · source 2 · source 3

Microsoft Copilot

Microsoft

Microsoft’s free AI assistant, plus Copilot built into Word, Excel, PowerPoint, OneNote, and Outlook with Microsoft 365.

For school: With Microsoft 365 Personal, Copilot works inside Office apps (Copilot in Excel needs AutoSave on, with the file in OneDrive). The free Copilot app includes chat and image creation.
Free tier: The Copilot app is free, with limited chat, image creation, and uploads (numeric limits not published).
Paid: Microsoft 365 Personal $9.99/mo or $99.99/yr (AI usage limits apply)
Student offer: 50% off Microsoft 365 Personal for verified college students (exact price: check site)
Training: Except for some groups, Microsoft uses Copilot conversations for AI training unless you opt out. Opt out under Profile → Privacy → “Training on conversation activity” (and voice). Not used for training: signed-in users under 18, signed-out users, and Copilot inside Microsoft 365 Personal or Family apps.
Retention: Conversation history is kept for 18 months by default. You can delete single chats or all history at any time.
Last checked: 2026-10-18 · source 1 · source 2 · source 3 · source 4 · source 5

Perplexity

An AI search engine that answers with links to its sources.

For school: Answers cite web sources. Pro and Education Pro add more Pro Searches, file uploads, premium models, and Learn Mode (listed for Education Pro).
Free tier: Free, with limited Pro Searches.
Paid: Pro $17/mo billed annually
Student offer: Education Pro $10/mo for verified students (SheerID)
Training: On Free, Pro, and Max, “AI Data Retention” is on by default, so your data may be used for AI training. Turn it off in Account settings → Preferences. Opting out only applies to data collected afterward.
Retention: No consumer retention period stated on the page we checked (check site).
Last checked: 2026-10-18 · source 1 · source 2 · source 3 · source 4

Grok

SpaceXSI (x.ai)

An AI assistant on grok.com, its own apps, and X, with chat, voice, and image generation (Imagine).

For school: Paid tiers are part of “The X Subscription.” Premium adds the latest Grok models, image and video generation, and more usage.
Free tier: Free, with limited chat requests and image generation.
Paid: Plus $8/mo · Premium $30/mo · Super $100/mo · Ultra $200/mo
Student offer: None published (check site)
Training: Your content may be used for training unless you turn off “Improve the Model” (grok.com: Settings → Data; app: Settings → Data Controls). Private Chat isn’t used for training. Feedback you send may still be used.
Retention: Deleted conversations and Private Chats are removed within 30 days (with safety, security, and legal exceptions).
Last checked: 2026-10-18 · source 1 · source 2

Open & local models (Ollama, LM Studio)

Various model makers

Free apps that download open models and run them on your own computer. LM Studio’s site names models like GLM, Kimi, and DeepSeek. Browse each app’s model library to see what’s available.

For school: Works offline once a model is downloaded. LM Studio includes offline voice transcription. Good for private notes, but quality and speed depend on your computer.
Free tier: Free to run locally. Ollama: “Running models on your own hardware is always unlimited.” LM Studio Free runs local models.
Paid: Optional cloud: Ollama Pro $20/mo ($200/yr) · LM Studio Bionic+ $20/mo
Student offer: None published
Training: Ollama says “your prompts are never stored or trained on.” LM Studio says its cloud services are zero data retention, and its voice data is processed locally.
Retention: Local chats stay on your device. Cloud options follow each company’s own terms (check site).
Last checked: 2026-10-18 · source 1 · source 2 · source 3 · source 4

Privacy basics for any AI tool

Find the training setting (names differ: “Improve the model,” “Keep Activity,” “AI Data Retention,” “Training on conversation activity”) and decide on purpose.
Use temporary, incognito, or private chat modes for anything personal.
Don’t paste other people’s information, grades, or anything your school treats as confidential.
Thumbs up or down feedback can send the whole conversation for training, even after you opt out (OpenAI, Anthropic, and SpaceXSI all say this).
Your school may provide its own AI accounts with different privacy terms. Ask your IT help desk.

FAQ

What's the difference between ChatGPT, Gemini, Claude, Copilot, Perplexity, and Grok?

They're all AI assistants, but each company's documented features differ. ChatGPT has a study mode on every plan. Gemini ties into Google apps and Gemini Notebook. Claude's Free plan includes Slides, Docs, and file creation. Copilot is built into Microsoft 365 apps. Perplexity answers with source links. Grok is part of the X Subscription. Open models can run on your own computer with Ollama or LM Studio.

Do AI chatbots train on my chats?

Often, unless you change a setting. As of 2026-10-18: ChatGPT (turn off 'Improve the model for everyone'), Microsoft Copilot (turn off 'Training on conversation activity'), Perplexity ('AI Data Retention' is on by default), and Grok ('Improve the Model') may use chats unless you opt out. Gemini depends on Keep Activity. Claude uses chats only if model improvement is allowed in Privacy Settings. Local models run on your own device.

Which AI assistants are free for students?

All six have free tiers as of 2026-10-18. Student offers include Google AI Pro free for a year for eligible U.S. college students 18+ (redeem by Dec 31, 2026), 4 free months of ChatGPT Plus (claim by Oct 31, 2026), Perplexity Education Pro at $10/month, and 50% off Microsoft 365 Personal.

What's the most private way to use AI for school?

Running an open model locally with Ollama or LM Studio keeps chats on your own computer. With cloud assistants, turn off training in settings, use temporary or private chat modes, and don't paste personal or sensitive information.

Can I trust what an AI model tells me?

Not without checking. Any of these tools can be wrong or make up sources. Verify facts against your course materials or the original sources, especially for anything you hand in.

Disclosure: no one paid to be on this page and it has no affiliate links. If we ever add one, it will be labeled right next to the link (for example, “paid link: we earn a commission”). Prices and student offers change often. We checked each one on the vendor’s own page on the date shown; confirm on their site before you pay.