Homework used to mean hours of searching, re-reading, and guessing your way to an answer you never really understood. The best students in 2026 do it differently. They keep an AI homework helper open in a browser sidebar and talk through the hard parts, then use a quick screen capture when they just need one thing on the page explained fast. Lensia is that helper: a Chrome extension whose main surface is a persistent sidebar chat you study inside, backed by a floating capture panel for on-the-page questions. This guide covers how it works, how to use it across every subject, and how to get started.
A quick note on honesty up front: a homework helper is a study aid. Lensia is built to help you learn the material, not to sit a graded test for you. Using any AI tool during a graded assessment where AI is restricted is academic dishonesty. Everything below assumes you are studying, reviewing, or checking your own work, never feeding it a live graded question.
What an AI homework helper actually is
An AI homework helper reads a problem and explains how to solve it. The good ones give you two ways in: a chat you can hold a real conversation in, and a fast way to pull a question straight off your screen so you never retype anything. Course material tends to live in PDFs, lecture slides, study platforms like Canvas, Moodle, and Blackboard, and scanned worksheets where copy-paste does not work, so both paths matter. Spend your time understanding, not retyping.
The sidebar chat: where the studying happens
The sidebar chat is Lensia's main surface, and it is on every plan. Open it from your Chrome toolbar. A chat docks in Chrome's side panel, next to your work, so your notes and the conversation stay on screen together.
It is the main surface because it keeps a whole conversation, not a single answer:
- Conversation history survives between sessions, so you can reopen last week's chemistry thread the night before the exam.
- Bookmarks save the explanations you know you will want again.
- A model picker at the top lets you start on a fast model and switch to a heavier one like Claude Sonnet 5 mid-thread when a concept needs more care.
Use it to work a topic out: paste a problem, read the walkthrough, then ask "why does step two hold?" and keep going until it clicks. On Basic and Pro, the sidebar can also run web search and fetch URL to pull a definition or formula from a live source, or read a link you hand it. On Pro, agent mode lets the AI chain several steps inside the sidebar, reading your open lecture notes, taking a fresh screenshot, and following up, before it answers. For the full mechanics of both surfaces, read how Lensia works.
The floating panel: fast answers on the page
Some questions do not need a conversation; you are reading, one thing stops you, and you want it explained without leaving the page. That is the floating panel, on every plan. Press Ctrl+Shift+X, drag a box around the problem, and a worked explanation floats up on top of the page in seconds. Ctrl+Shift+F repeats the last capture area, so a page of similar practice problems takes one keypress each, and Ctrl+Shift+E hides the panel with no on-screen trace.
The panel has an Ask Mode switch, also on every plan including Free. Flip it on and the panel becomes a custom-question box: type your own prompt and attach up to three images from your screen or device. That covers what a single screenshot cannot hold, like a multi-image comparison or a wordy concept you want explained in your own words.
The rule of thumb: sidebar to talk a concept through, panel to grab one thing fast. Both share the same models and the same usage budget.
Custom instructions: make the AI talk to you
Custom Instructions are the feature most students underuse. You save three short blocks that travel with every capture and every chat: a nickname the AI calls you, a companion style (direct and terse, warm, professorial, whatever you like to read), and an about you block describing what you are studying and where you want help. If you are taking organic chemistry as a pre-med, say so. The AI stops re-explaining things you already know and pitches answers at your level.
Reasoning mode: the toggle that pays off on hard concepts
Reasoning mode is a single on/off toggle that tells the model to slow down and check its own work before answering. There are no Low, Medium, or High levels; it is on or off. Leave it off for quick recall and vocabulary, and turn it on for multi-step math or logic where one early slip wrecks the rest of the walkthrough. The wait grows by a couple of seconds; the quality on the questions that need it grows far more.
Best subjects for AI homework help
Multiple choice
The AI reads a practice question and its options and explains why one holds up and the others fall apart. Attempt it yourself first, then check your reasoning against the walkthrough. That is what makes the idea stick when it reappears later. More on this in AI for multiple-choice practice.
Math and calculations
Capture a problem you are stuck on, or paste it into the sidebar, and the AI identifies the formula, shows the step-by-step calculation, and explains the final result with units. Solve it yourself first, then compare your steps to find the slip. The full workflow is in AI for math homework.
Science: biology, chemistry, physics
Science mixes concepts with calculations, and the AI handles both, from "describe how ATP synthase produces energy" to a molecular-weight problem. For diagram questions where the picture carries the meaning, Lensia sends the full image to a vision-capable model so the explanation can reference what is actually in the figure.
History, English, and social sciences
For essay prompts and short-answer practice, capture the prompt or paste it in the sidebar and get a structured outline of how a strong response is organized. Use it as a model for structure, then write in your own voice from your own reading. The AI is also good at surfacing themes, summarizing arguments, and drilling dates.
Coding and computer science
Paste a problem into the sidebar and the AI walks through an approach and the logic behind it so you can write the code yourself, or debug your existing solution when you include the error you are hitting.
How to use it well
Start with understanding, not answers. Every response comes with reasoning, and reading it is where the learning happens. The same idea shows up in research on effective study strategies. A workflow that works:
- Attempt the problem yourself first.
- Capture it with Lensia, or paste it in the sidebar, and read the full explanation, not just the final answer.
- Close the panel and rebuild the solution from memory.
- Move on once you can say why the answer is correct.
Check your work, do not skip it. After your own attempt, compare answers and ask a follow-up on any gap. The goal is to close the gap in your understanding, not to swap your work for the AI's. Generate your own practice too: ask the sidebar for fresh questions on a topic from your notes, attempt them under a timer, then have the AI explain what you missed. More techniques in how to study smarter with AI.
Choosing the right AI homework helper
Not all AI homework tools are equal. Here is what to weigh:
| Feature | Why it matters |
|---|---|
| Sidebar chat | A real conversation beats one-shot answers for actually learning |
| Screenshot capture | No retyping; works on any platform |
| Local text reading | Keeps screenshots off external servers |
| Model quality | The depth of the explanation depends on the model |
| Speed | Slow tools break your study flow |
| Step-by-step explanations | Worked reasoning is what turns an answer into learning |
Lensia covers all six. It runs a wide model lineup (Quick and Standard, such as GPT-5.4 Nano, Gemini 3 Flash, and Claude Haiku 4.5, with Advanced models like GPT-5.4, Claude Sonnet 5, and Gemini 3.1 Pro), and reads text on your own device so screenshots stay local in most cases. Compare it against other tools in the best Chrome extensions for students.
Getting started with Lensia
Setup takes under two minutes:
- Install from the Chrome Web Store.
- Sign in with Google in the extension to activate (Google sign-in only).
- Open the sidebar and ask about the problem you are stuck on.
- Capture the next on-page question with Ctrl+Shift+X.
The Free plan is free and includes the sidebar chat, the floating panel, Ask Mode, and the Quick and Standard models. Basic gives about ten times the Free usage, plus reasoning mode, web search, fetch URL, custom instructions, and the Advanced model lineup. Pro has the highest usage allowance and adds agent mode in the sidebar, plus Auto-Solve for Vocabulary.com practice. If you would rather not pick a model, Lensia Max chooses one from the Quick and Standard lineup for you at a 15 percent discount.
What to expect day one
The best AI homework helper stays out of your way while you learn. Open the sidebar and talk through the problem you are stuck on, read the reasoning until it makes sense, then solve the next one yourself. When something on the page stops you mid-read, capture it and keep moving. It works across subjects, from one-line vocab to multi-step physics, and the text reading runs on your device so screenshots stay local in most cases.
Install Lensia and start learning faster today.