A free answer checker for any worksheet

Three things to know before you start

Quick start

1. Open Answer Checker on the computer or iPad your students will use. Always open it from the same web address, because browsers save data separately for each address.
2. Tap Teacher at the top right and enter the PIN 1234. Go to Settings, set a new PIN, and write it down.
3. Open Answer sets. A sample long division set is already there so you can try it. Choose New set to make your own, or Import from file.
4. In the editor, name the set, pick a type for each problem, enter the answer for each problem, and set up your students. Then Save.
5. Number the problems on your worksheet to match the labels in the answer key (1, 2, 3 or A, B, C).
6. Tap Open student station. Students take it from there.

Your students

Each assignment has its own student list. You choose how students identify themselves.

After each answer, the screen shows the result with two buttons. Enter another answer goes back to the problem list, so a student can keep going without entering a PIN again. I’m done signs out. If nobody taps anything, it returns to the student list after four seconds, which signs the student out so the next student can go. If a student runs out of tries on a problem, it locks. To unlock it, open Progress, tap that cell, and choose Reset this problem.

Student PINs: keep progress private

If two students compete, you may not want them looking at each other’s progress. Turn on Student PINs in the editor. Each student gets a 3-digit PIN, so only they can see their progress and check answers.

• Give everyone a random PIN fills in different 3-digit PINs for the whole class. Then use Download PIN list or Copy PIN list to print them and hand them out.
• A student with no PIN signs in without one, so you can protect only some students.
• The PIN keeps students from viewing each other’s progress. It’s a classroom guard, not strong security.

Classes: set up your students once

If you teach the same students all year, you don’t have to type their names for every assignment. In Teacher, open the Classes tab and make a class. A class is a student list, with an optional 3-digit PIN for each student. Every assignment that uses the class shares it.

1. Open Teacher, then Classes, and tap New class.
2. Name the class, choose Names or Numbers, and add your students. Paste a list of names is the fastest way. If you want PINs, use Give everyone a random PIN and then copy or download the list to hand out.
3. Save. Then open an assignment in Answer sets (a new one, an imported one, or an existing one) and pick your class from the Class box at the top, next to the set name. You won’t need to type names again.

• One PIN per student, all year. A student’s PIN comes from the class, so it is the same in every assignment. Turn Student PINs on or off for each assignment.
• Changes follow everywhere. Add or rename a student in the class, and every assignment using it is updated. Removing a student asks you first, because they disappear from those assignments and their results there stop showing.
• Already typed a list? Open that assignment and choose Save this list as a class. Its results stay with it.
• Results stay with each assignment. Classes only save typing. Answer Checker doesn’t combine results across assignments, and it isn’t a gradebook.
• Deleting a class is safe. Assignments that used it keep their own copy of the list and PINs.
• Classes are saved in this browser like everything else, and they are included in your backup. Backup files contain student names and PINs as plain text, so keep them private.

Setting up an answer set

Answer types: pick one for each problem

A test can mix question types. Each row in the answer key has its own type, and new rows start with the same type as the row above, so a run of ten multiple-choice problems is quick to set up.

Your own words on the choices

For Multiple choice and Select all, the choices are the letters A, B, C by default. Switch a problem to Own words to type what each button says, like milk and juice, or 187 ÷ 4. Mark which ones are correct. A choice you leave blank keeps its letter. Each problem has its own wording, so every question can be different.

More than one answer per problem

For problems like division, or several blanks in one sentence, choose how many answer boxes the problem has, up to five. Under Name, type what each box is called, such as Quotient and Remainder, so students know which box is which. A student must get every box right.

Star a problem to double-check

Tap the star at the left of a problem to flag it, for example when the key says more than one answer works. Students never see the star. In Progress, a star appears in the corner of that problem’s cells and on its column heading, so you know where to look.

Other answer-key tips

• Put | between answers that should all count, like 0.5|1/2.
• The Note column is only for you. Students never see it.
• Paste a list fills the key from one answer per line. For two boxes you can type 6 R16.
• Label 1, 2, 3 and Label A, B, C relabel all the problems at once.

Import an answer key from a file

Save a spreadsheet as a CSV file, then use Import from file on the Answer sets page, or Import file inside the editor. The first row is an optional Set name, then a header row, then one row for each problem. Before anything is saved, Answer Checker shows what it understood, problem by problem, and lists anything that needs a look.

Set name,Unit 3 practice
Problem,Type,Choices,Options,Box names,Answer 1,Answer 2,Answer 3,Answer 4,Answer 5,Note,Star
1,Multiple choice,4,,,D,,,,,,
2,Numbers,,,Quotient|Remainder,46,9,,,,745 ÷ 16,
3,Select all,3,dog|ran|quickly,,A C,,,,,,
4,Numbers,,,,70000,20,50,60,,more than one answer works,Yes

• Type for each problem: Numbers, Text, Numbers and text, Multiple choice, Select all, or True or false.
• Choices is 2 to 6, for Multiple choice and Select all.
• Options are your own words for the choices, separated by |. Leave it empty for letters. The answer is then the letter of each correct choice by position, so A is the first option.
• Box names label the answer boxes, separated by |.
• Answer 1 to Answer 5 hold one answer each. For Select all, put the letters in Answer 1 with spaces, like B D.
• Put Yes in Star to flag a problem, and the reason in Note.

Older files still work: an Answer type line with named answer columns, and a plain text file with one answer per line.

Have the answers as a PDF or a photo?

Open How the import file works on the Answer sets page. It has a ready-made prompt that you can copy into an AI chatbot such as ChatGPT, Claude, or Gemini. Attach your answer key, and the chatbot turns it into a CSV file in the right format, with a type for each problem, the right answer boxes for problems like division, and a star on any problem where the key says more than one answer works. Then choose Import from file.

Live assignments: no setup between classes

You can have as many answer sets as you like, and turn Live on for all of the ones students should be able to choose. A teacher with three periods can put in Period 1, Period 2, and Period 3 once and leave them all live.

• When more than one assignment is live, the top of the student screen shows the current assignment’s name. Students tap it and choose another one. No PIN is needed.
• The station stays on the assignment they chose, even after reloading, and goes on working the way it does now.
• Each assignment has its own answer key, student list, PINs, and results, so nothing gets mixed.
• Turn an assignment Off to hide it from students. Its results are kept, and you can still view them under Progress.

Name your sets clearly, like “P2 Fractions,” since that is what students see when they choose.

Rules you can change

These are in the answer set editor, so each worksheet can have its own rules.

Running a class

Progress

The Progress tab shows a grid of students and problems for any assignment. The grid is color coded. Green is right on the first try. Yellow is right after a miss (a check with a number) or still being worked on (an X with a number). Red is locked. Accuracy bars and percentages are green at 80% and up, yellow from 50 to 79%, and red under 50%. Tap any cell to see exactly what the student typed.

• Stars. A star in the corner of a cell means you flagged that problem to double-check in the editor.
• Mark correct. Tap a cell, then Mark correct, when an answer was right but the key didn’t accept it. The cell turns green with a small T, the student’s problem counts as solved, and their tries stay on record. You can do this for a locked problem, or for one a student did on paper. Undo mark takes it back.
• A problem you marked correct counts as one correct answer in accuracy, and the student’s misses on it are left out.
• Class accuracy is the share of all submitted answers that were right.
• Most missed problem shows which one the fewest students solved, so you can reteach it.
• Each student has an accuracy bar. Needs help first sorts the lowest to the top.
• Export CSV saves every answer to a file for your gradebook or records.

Between classes

Results belong to each answer set. To run the same worksheet in another period without mixing results, use Duplicate on the Answer sets page, or Clear results to start fresh.

Student devices: more than one student station

Instead of one device where every student enters answers, you can use several. Each extra device is a student station that works exactly like the one on your computer. Your computer stays in charge: it checks every answer and keeps all the results, so keep it open and awake while students are answering.

1. On your computer, open Teacher, then Student devices, then Start session.
2. On each student device, do whichever is easiest:
   • Scan the QR code on your screen with the device’s camera. It opens the student station already connected.
   • Or open Answer Checker on the device, and on the Tap your number screen tap the small link icon in the bottom right corner. Type the code, then tap Connect. Nothing on the device is changed or saved.
   • Or open the student link (tap Copy student link and send it to the device), or open the join address shown on that page and type the code.
3. Students tap their number or name and work as usual. Their answers show up in Progress on your computer right away.
4. When you are done, tap End session. Every student device is told the class has ended. A session also ends on its own after 2 hours with no activity, or after 12 hours in all, so a forgotten session does not stay open. To use a device on its own again, open Answer Checker without the code, or tap Use this device on its own on its join screen.

Good to know

• Answer keys never leave your computer. Student devices get the problems and the type of each question, but never the answers, your notes, or your stars.
• PINs are checked by your computer. A student device only learns whether the PIN was right.
• Names. Assignments where students tap their name only open on student devices if you turn on Show student names on student devices. The names pass through while the session is open and are not stored. Numbers need no setting.
• If your computer closes or loses its connection, student devices say they are waiting for it. An answer sent while your computer is away is not saved anywhere, and the student is told right away.
• Changes you make to a live assignment, or turning one on or off, reach student devices within a moment.
• Student devices save nothing in their own browser.
• Device limit. Up to 2 student devices can join a session for free. A student device that is turned away sees “This class is full”, and you see a note on the Student devices page. An unlock code allows more. Paste it into the Device limit box on that page and tap Save and check. It is saved on that computer only (not in backups) and sent to be checked each time you start a session. Codes have an end date. If a code stops working you keep the free limit. People who have bought one of Formatio Forge’s apps can contact the developer to request a free code.
• If student devices are not available, Answer Checker keeps working normally on your computer.

Install on your iPad (optional)

You can add Answer Checker to your iPad’s Home Screen so it opens like an app, full screen, with no Safari bars. It’s optional, and everything works the same either way.

• Full screen. It opens from its own icon.
• Works without internet. After it has loaded once, it opens even with no Wi-Fi.
• Safer saved data. Safari can clear a browser tab’s saved data if you go about a week of Safari use without visiting the site. An installed app isn’t cleared that way.

1. Open Answer Checker in Safari on your iPad.
2. Tap the Share button, then Add to Home Screen.
3. Open Answer Checker from its new icon.

Where your data lives, and how to back it up

Your answer sets, classes and student lists, results, settings, and PIN are saved in your browser’s local storage for this web address. They are not sent to a server, and Formatio Forge can’t see or recover them. That keeps student information out of anyone else’s hands, and it has some consequences you should know about:

• Each computer is separate. Another computer, another browser, or another browser profile starts out empty.
• Use one web address. A page at www.example.com and one at example.com save data separately.
• Clearing browser data erases it. That includes clearing cookies and site data, and some school computers do this automatically when you log out.
• Private or incognito windows don’t keep anything. Everything is gone when the window closes.
• Safari can clear a browser tab’s data. If you go about a week of Safari use without visiting the site, Safari may delete what a tab saved. Installing it on the Home Screen avoids that.
• An installed app and a Safari tab keep separate data. Move your sets with Export backup and Import backup.

Back up your data (your responsibility)

Answer Checker is an offline tool. There is no cloud copy, no account, and no one at Formatio.Forge who can restore what you lose. If your browser data is cleared, your computer is wiped or replaced, or the browser is reset, your answer sets and results are gone unless you saved a backup file.

1. Open Teacher and enter your PIN. The Back up now button is at the top of every Teacher page.
2. Tap Back up now, or go to Settings and choose Export backup. A file named answer-checker-backup.json is saved to your device (on an iPad, check Files, then Downloads).
3. Move that file somewhere safe that isn’t this browser: a USB drive, your school’s file storage, or an email to yourself. Keep it where students can’t reach it.
4. Settings and the top of each Teacher page show when you last made a backup. Make a new one after any big change, and at least before breaks and before the school computer is updated or replaced.

Restore from a backup

1. Open Answer Checker, then Teacher and Settings.
2. Choose Import backup and pick your backup file.

Move to another computer, iPad, or browser

Because nothing syncs, a new device starts empty. To move:

1. On the old device, open Teacher, then Settings, and choose Export backup.
2. Get the file to the new device: email it to yourself, use a USB drive, AirDrop, or your school’s file storage.
3. On the new device, open www.formatioforge.com/answer-checker/ in the browser you will keep using. Tap Teacher. The new copy’s PIN is 1234 until you import.
4. Open Settings, choose Import backup, and pick the file. Your sets, student lists, PINs, and results come with it, and your teacher PIN becomes the one from the old device.
5. Check that your answer sets look right, and then make a fresh backup from the new device.

The same steps move data from a Safari tab to the installed Home Screen app, since they keep separate data.

PINs

The teacher PIN guards the Teacher area. Five wrong tries in a row lock it for 30 seconds.

If you forget your teacher PIN

There’s no “forgot my PIN” option, because an easy reset would let anyone take over your Teacher area. The only way back in is to clear this site’s saved data in your browser’s settings. That erases all of your answer sets, student lists, results, and settings and puts the PIN back to 1234. If you kept a backup file, you can import it afterward.

Teacher and student PINs are classroom guards, not strong security. They stop students from tapping into the wrong place or peeking at a rival’s progress. They aren’t meant to protect against someone who knows how to inspect the browser.

Privacy statement

Last updated October 13, 2026

Answer Checker is built so that we never collect or keep information about your students or you. This page explains what that means in practice.

What we collect

Nothing about you or your students. Answer Checker has no accounts or logins. It never asks for email addresses, birth dates, locations, or any other personal information. By default, students are identified only by a number. If you choose to use names, you type them in yourself, and they stay in your browser.

What stays in your browser

Your answer sets, student lists, results, settings, and PINs are stored in your browser’s local storage on your own device. We don’t receive them, and we can’t see, access, or recover them. They stay there until you erase them with Erase everything in Settings, or by clearing your browser’s site data.

Nothing is sent anywhere, unless you start a student-devices session

By default, after the page loads, Answer Checker makes no requests to any server. Your students’ answers, your answer keys, and everything else you enter never leave your device, except in files you choose to export.

The one exception is the optional Student devices feature. Only if you tap Start session, your computer and the student devices you connect talk through a small relay run by Formatio Forge at checker-relay.formatioforge.com. While the session is open, these pass through it so that other devices can work as student stations: the problems on your live assignments (labels, question types, the wording of choices, and answer-box names), the student list (as numbers, or as names only if you turn on Show student names on student devices), each student’s progress, the PIN a student types so your computer can check it, and the answers students type. The relay is built only to pass these along, and it does not store them. It runs on Cloudflare’s network, which also hosts formatioforge.com. The session ends when you end it, after 2 hours with no activity, or after 12 hours. If you saved an unlock code, it is sent along when you start a session so the relay can check it. The relay does not keep the code. It keeps anonymous daily totals only (how many sessions and student devices, and how many were turned away or ended by themselves), with nothing that says who or what. Your answer keys, your saved student PINs, your notes and stars, and your saved results never leave your computer. Student devices do not save anything in their browsers.

Cookies, trackers, and third parties

Answer Checker does not set cookies, and it contains no advertising, analytics, or tracking code. Its fonts and images are included in the page or come from formatioforge.com, so loading it doesn’t contact any other company’s servers.

Notes about Formatio Forge’s own apps

The teacher area, and this page, include small notes about other apps made by Formatio Forge. They are links to formatioforge.com and to the App Store, not third-party ads. They never appear on the screens students use. The pictures in them are stored with the tool, so showing them doesn’t contact any other server, and Answer Checker does not track whether you click them.

Installing on a Home Screen

If you add Answer Checker to your Home Screen, your device stores a copy of the tool’s files, and a small helper called a service worker, so it can open without internet. Those files contain no personal information. You can remove them by deleting the Home Screen icon or clearing the site’s saved data.

Server logs

Like any website, the service that delivers this page, Cloudflare, processes technical information such as your device’s IP address, browser type, and the time of a request in order to deliver the page. Answer Checker doesn’t add any student information to those requests.

PINs

Teacher PINs and optional student PINs are stored in your browser as plain text and included in backup files. They are a convenience for the classroom, and they are not meant to be strong security.

Children and student information

Because Answer Checker doesn’t collect personal information, there are no student accounts or profiles for us to hold. You decide what you type into answer sets, notes, and student lists, so please keep personal information to a minimum. First name and last initial is plenty. Anything you type stays in your browser, but it would be included in backup files and CSV exports. Teachers are responsible for following their own school’s and district’s rules about student data.

AI chatbots (optional)

Answer Checker doesn’t connect to any chatbot. The sample prompt on the Answer sets page is only text that you can copy. If you choose to upload an answer key to a chatbot, that is between you and that service, and its own privacy terms apply. Please don’t upload anything that contains student names or other personal information.

Backups and lost data

Answer Checker is provided free, as is, and works offline. Your data is stored only on your own device, and Formatio.Forge cannot access, back up, or restore it. Making and keeping backups is your responsibility, and Formatio.Forge is not responsible for any data that is lost, erased, or corrupted, including through clearing browser data, a browser or device problem, a lost PIN, or importing a backup over newer data.

Files you export

Backup files and CSV exports are saved to your device. They contain your results, and backup files also contain your PIN, and any student names and PINs, as plain text. Keep them private.

Your choices

You can delete everything at any time with Erase everything in Settings, or by clearing your browser’s site data. Nothing remains on our side, because nothing was ever sent.

Changes and questions

If this statement changes, we will update the date at the top. Questions are welcome at [email protected].

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