You are stuck on problem 7, it is late, and the textbook example looks nothing like your question. A math solver scanner fixes the first part of that mess: point your phone at the page and a worked solution shows up a few seconds later. The second part, actually understanding it, still depends on you and on which app you pick.
We built Acuity because we wanted a scanner that teaches instead of just answering, so we have strong opinions here. This guide covers how scanning works, which apps are worth your time, how to get clean results, and where these tools fall short.
How a math solver scanner actually works
Under the hood, there are two jobs. First, the app reads your photo and turns it into text and symbols. That is the OCR part, and it is where most scanning failures happen. Second, an AI model solves the extracted problem and writes out the steps.
That split matters. If the app reads a "7" as a "1", the solution will be confidently wrong, and the maths on top will be flawless. So when a result looks odd, check what the app thinks the problem says before blaming the solver.
A good scanner also lets you fix the input. Cropping, retaking the photo or typing the exercise by hand are not nice extras. They are how you rescue a bad scan.
What to look for in a homework scanner app
Every app on the App Store claims to solve everything. These are the criteria that actually separate them.
- Step-by-step explanations. A bare answer teaches nothing and won't help on exam day.
- Subject coverage. Some tools handle only math. Others cover physics, chemistry, biology and more.
- Input options. Camera only is limiting. Photo library, PDF and manual entry save you when the page is crumpled or the worksheet is a file.
- Follow-up questions. You will not understand every step. Being able to ask "why did you move that term?" is huge.
- Practice afterwards. Solving one problem is easy. Solving the next three alone is the real test.
- Honest free tier. You should know what you get before the paywall shows up.
Speed is a minor factor. Anything that returns a solution in under 15 seconds feels instant when you compare it to flipping through a textbook.
The best homework scanner apps compared
Here are the main names for scanning homework on iPhone. Ratings below come from the App Store figures we track for each app.
Photomath
Photomath is owned by Google and carries a 4.8 rating from about 733,000 ratings. It focuses on math only and has very strong brand recognition. It is excellent at showing step-by-step algebra, but there are no study sheets or quizzes. If your homework is purely math, it is a safe pick. If you also need to review biology tomorrow, you will switch apps.
Gauth
Gauth is the biggest name by volume, with a 4.8 rating from roughly 1.4 million ratings. It works as a broader AI study companion with AI chat and multi-subject support, and it is especially strong on math and science scanning. Our Gauth alternative comparison goes deeper if you are weighing it up.
Answer.AI and Question.AI
Answer.AI (4.7, about 166,000 ratings) is a scan-and-ask AI tutor with multi-subject coverage, but no study sheet or quiz generation. Question.AI (4.7, about 156,000 ratings) scans and solves across all subjects and is a serious option for pure exercise solving, though it has no study sheet generation.
Acuity
Acuity is our own app, so take this with the right amount of salt. It scans from the camera, but also accepts images from your photo library, PDFs and typed exercises. Solutions come back in around 12 seconds on average. You can then ask Mathilda, the in-app assistant, to explain any step, and generate similar practice exercises from the one you just solved. Study sheets and quizzes live in the same app.
| Feature | Photomath | Gauth | Answer.AI | Question.AI | Acuity |
|---|---|---|---|---|---|
| Camera scanning | ✅ | ✅ | ✅ | ✅ | ✅ |
| Subjects | ➖ Math only | ✅ Multi-subject | ✅ Multi-subject | ✅ Multi-subject | ✅ Multi-subject |
| AI chat | ➖ Not a focus | ✅ | ✅ | ➖ Not a focus | ✅ |
| Study sheet generation | ❌ | ➖ Not a focus | ❌ | ❌ | ✅ |
| Quiz generation | ❌ | ➖ Not a focus | ❌ | ➖ Not a focus | ✅ |
A fair caveat: the table reflects the overlap and notes we track for each competitor, not a full audit of every feature. Features change often, so check the App Store listing before you commit to anything.
How to scan a math problem and get a clean result
Whatever app you use, the same habits make the difference between a perfect solution and a frustrating one. Here is the routine we recommend.
- Clear the shadow. Hold the phone directly above the page, not at an angle, and avoid your own hand's shadow across the equation.
- Frame one exercise at a time. Scanning a full worksheet confuses the reader, and the app may solve the wrong line.
- Crop tight. Remove margins, doodles and the problem above or below.
- Pick the right subject if the app asks. Subject choice shapes the quality of the solution.
- Check the detected text. If the equation was misread, fix it or type it manually.
- Read the steps, then close them and try a similar problem yourself.
Step six is where most students cheat themselves. The scanner is a tutor you can interrupt, not a vending machine for answers.
Scanning beyond the camera: PDFs, screenshots and typed problems
Lots of homework now arrives as a PDF or a screenshot from a class portal. Photographing your own laptop screen produces moiré lines and glare, and the OCR hates it. Importing the file directly is cleaner.
In Acuity you can import an image from your library, bring in a PDF or just type the exercise. One honest limitation: when you import a PDF, diagrams and images inside it are not taken into account. If the exercise relies on a figure, such as a geometry triangle or a graph, send a photo instead so the visual comes through.
Typing is underrated for short problems. A one-line equation takes ten seconds to enter and removes any OCR risk entirely.
Can you scan homework for free?
Mostly yes, with limits. Nearly every scanner offers a free allowance, then asks for a subscription once you push past it. That is how these apps pay for servers, and it is fair enough.
For Acuity, the free plan includes up to 12 exercises per 24-hour period, 10 messages a day with Mathilda and up to 6 revision sheets. Those numbers are indicative and may change over time. Premium unlocks unlimited exercises, unlimited chat and unlimited quizzes, on a monthly or yearly plan managed through your Apple account.
For most students, twelve scans a day is plenty for regular homework. It gets tight during exam weeks, which is the honest case for upgrading, and only then.
Where a math solver scanner falls short
No tool is perfect, and pretending otherwise would be silly. Scanners make mistakes, and AI-written solutions can contain errors, especially on long multi-step problems or ambiguous wording.
- Handwriting that is messy or cramped is the number one cause of misreads.
- Word problems with missing context can produce a confident but wrong setup.
- Teachers often want a particular method, and the app may pick another valid one.
- Copying solutions without reading them leaves you stuck on the test, when no phone is allowed.
If an answer looks off, do not argue with it in your head. Re-scan, ask a follow-up question, or compare with a second app. Checking two sources takes a minute and catches most errors.
Which scanner should you pick?
If your life is pure math and you want the most polished step-by-step view, Photomath is hard to beat. If you want a huge community and broad AI help, Gauth is a reasonable choice. Our Photomath alternative page lays out where each one wins.
Choose Acuity when you want the scan to be the start of studying rather than the end of it. Solve the exercise, ask Mathilda to unpack the confusing step, generate a similar exercise to practice, then turn the topic into a study sheet or quiz before the exam. One app, one flow.
Whichever you try, the goal is the same: use the scan to understand the method, then prove it to yourself with a problem you solve alone. If you want to test the camera flow on your own homework, download Acuity for iPhone on the App Store and scan tonight's toughest problem.