If you substitute teach, six tools do the work you actually face: Knowt for building the plan the absent teacher never left, Brisk Teaching for making sense of the materials already open on the classroom computer, Diffit for pitching a text at a grade you weren't expecting, Flip Education for a room with no working devices, MagicSchool for everything else, and Perplexity for the period where you have to teach a subject you never studied. All six run from a personal account. That last detail matters more than any feature, and the reason sits in the vendors' own privacy policies.
This post is for day-to-day and long-term substitutes, called supply teachers in the UK and Ireland, and for the building administrator who hands them a badge and a room number. It is not a list of tools for a teacher writing sub plans in advance; those live in the lesson planning and resource creation category.
How I built this list
The pool was the 50 tools in the directory's lesson planning and resource creation category, plus the 41 in student engagement and gamification, filtered by one hard rule: a substitute has to be able to use it today, from their own account, without a district single sign-on. Then I weighed fit for a substitute's real jobs, what the vendor documents about student data, honest pricing, and whether the tool leaves the teaching judgment with the person standing in the room.
Nobody pays to appear here. Vendors cannot buy placement, and I left tools out.
I left out Curipod, which turns up on almost every AI lesson-generator list, including our own directory card. Its homepage headline now reads "Writing Practice Students Love," and its pricing page describes weekly writing sessions with character-capped student responses rather than whole-lesson generation. That is a fine product; it is no longer the emergency lesson generator the listicles describe. I also left out Conker, whose pricing loads through a script our checks could not read, so its free-tier limits could not be confirmed. And I left out anything gated behind Clever or ClassLink, which is exactly what a substitute does not have.
Pricing and features verified September 10, 2026.
By the numbers, and why the free tier decides everything
Substitutes are paid by the day. They will not expense a subscription, which makes the free tier the whole ballgame.
Of the 126 tools in the directory, 74 are freemium and 11 are free outright. The gaps are as telling as the totals: 45 tools state nothing about FERPA, 45 state nothing about COPPA, and 48 do not say where they host data. Thirty-six of the 126 carry an independent 9ine security assessment. Those blanks are our record of what vendors publish, not evidence of wrongdoing, but a substitute working outside a district contract is precisely the person who has to read them.
The protection you think you have comes from a contract you are not on
Here is the thing almost no one tells a substitute, and it is written plainly in the vendors' own documents.
When a district buys an AI tool, the student-data protections come from the agreement the district signs, not from the software. Brisk Teaching's privacy notice says the company acts as a "School Official" under FERPA when schools "enter into a contract with Brisk to use the Service, such as Brisk's Student Data Privacy Addendum or another similar set of protections." MagicSchool's privacy policy draws the same line from the other side: "This Privacy Policy does not apply to information that we process as a service provider on behalf of schools," because that processing "is governed by our agreements with such Customers."
Read those two sentences together and the picture is clear. A teacher on the district's licensed account sits inside a signed agreement. A substitute who downloads the same extension to a personal free account sits outside it, using the consumer product, under the consumer terms.
FERPA, the Family Educational Rights and Privacy Act, is described by the US Department of Education's Student Privacy Policy Office as the federal law giving parents "the right to have some control over the disclosure of personally identifiable information from the education records." The practical consequence for a substitute is short: put nothing into any of these tools that identifies a student. Not a name, not a grade, not a behavior incident, not the note you were asked to leave about third period. Type "a ninth grade class of 28," never "Marcus."
That rule costs you nothing. Every job below works fine on anonymous inputs.
The six, compared
| Tool | Best for | Pricing (checked Sept 10, 2026) | Grades | Min age | Privacy (vendor-declared) | Data hosted | Independent security assessment |
|---|---|---|---|---|---|---|---|
| Knowt | Building the missing plan | Free for teachers | All grades | No minimum | FERPA, COPPA, GDPR | US | Yes (9ine) |
| Brisk Teaching | Using what's on the screen | Free tier; paid quote-based | Not stated | Not stated | Not stated in our record | Unknown | Yes (9ine) |
| MagicSchool | The all-purpose toolkit | Free; Plus $8.33/mo annual | Not stated | Not stated | Not stated in our record | Unknown | Yes (9ine) |
| Diffit | Re-leveling a text fast | Free tier; school pricing on quote | Not stated | Not stated | Not stated in our record | Unknown | No |
| Flip Education | A room with no devices | 5 free lessons; $7.99/mo | Pre-K to post-secondary | 18+ | GDPR | US | No |
| Perplexity | Content you never studied | Free tier; paid unverified | Not stated | Not stated | Not stated in our record | Unknown | Yes (9ine) |
The privacy column records what each vendor declares, not an audit. "Not stated in our record" means our directory entry is blank, which is not the same as non-compliance. The security assessment column is the independent one.
Best for building the plan that was never left: Knowt
Knowt is the best fit for walking into a room with no plan because it has a purpose-built substitute plan generator that is free and produces a timed agenda rather than a wall of prose.
You give it grade, subject, and whatever the office told you, and it returns a formatted agenda with time-stamped activities, objectives, a materials list, and classroom management notes. The time stamps are the part that saves you: a substitute's problem is rarely "what shall we do," it is "what do we do for the next 47 minutes."
What sets it apart from MagicSchool's general lesson generator is the shape of the output. MagicSchool writes you a lesson plan. Knowt writes you a period.
Knowt also has the most complete safety record of any tool here. It is the only one of the six declaring FERPA, COPPA and GDPR together with US hosting and no minimum age, and it carries an independent 9ine assessment.
Watch out for: the plan is only as good as the context you give it, and you usually have very little. A generated agenda for "10th grade biology" will be generic. Spend two minutes reading whatever is on the teacher's desk first.
Pricing: free for individual teachers, including "unlimited AI usage for students & teachers on teacher-owned files," with up to 20 "ultra" features a month; schools and districts can buy licenses (Knowt for teachers, checked September 10, 2026).
Safety: Knowt declares FERPA, COPPA and GDPR compliance, hosts data in the US, sets no minimum age, states it collects student data but does not share it with third parties, and honors deletion requests. It holds an independent 9ine security assessment. As a substitute you will not be creating student accounts, so keep your use to teacher-owned files and check with the building administrator before you ask a class to log in to anything.
Best for using what is already on the screen: Brisk Teaching
Brisk Teaching is the best fit for a substitute who inherits materials rather than making them, because it works as a browser extension on top of whatever document or webpage is already open.
The teacher left a Google Doc, a slide deck, and a link. Brisk sits in the browser and acts on those directly: level the reading up or down, generate questions from the page, turn an article into a discussion. You are not retyping the lesson into a chatbot. You are working the artifacts you were handed.
That is what sets it apart from Diffit, which is excellent at re-leveling but wants you to bring it a text. Brisk goes to the text. Directory readers rate it 4.77 from 35 reviews, the highest count of any tool in this list.
Watch out for: it is a Chrome and Edge extension, so it needs a browser you can install into. On a locked-down classroom machine you may not be able to, and installing an extension on someone else's logged-in profile is a bad idea regardless. Use your own device.
Pricing: free plan with 20+ tools, the extension, feedback tools and Brisk Boost; Premium and Intelligence tiers are custom pricing with no public figure (Brisk plans, checked September 10, 2026).
Safety: Brisk's privacy notice states it acts as a "School Official" under FERPA where a school has signed a contract such as its Student Data Privacy Addendum, treats student data as confidential, and says it "will not collect personal data from children under 13 without appropriate consent or authorization." Our directory record does not carry a FERPA, COPPA or hosting declaration, and the notice does not say whether student data is used to train models. On a personal free account you are outside any district addendum, so keep student names out of it.
Best for re-leveling a text you weren't expecting: Diffit
Diffit is the best fit for the moment you discover the reading is three grade levels off, because it rewrites any article, PDF, URL or video transcript to a level you choose and prints.
Substitutes get moved. You accepted 11th grade English and you are covering 7th by second period. Diffit takes the passage the teacher left and gives you the same content at a workable level, with a vocabulary list and questions attached, in about a minute. It translates into 70+ languages, which matters in a class you do not know well enough to have been briefed on.
Against Brisk, the trade is direction of travel: Diffit produces a cleaner printable packet, Brisk works faster inside an existing document.
Watch out for: the free tier only lets you reach resources created in the last 90 days (Diffit pricing). For a substitute that is rarely a problem, since you need today's packet today, but do not treat it as your archive. Directory readers rate it 4.20 from 5 reviews, the thinnest sample here.
Pricing: free Basic plan with classroom-ready content, PDF download and printing, and 90-day access to what you made; Diffit for Schools is a flat annual subscription tiered by enrollment with no public figure (Diffit pricing, checked September 10, 2026).
Safety: our directory record shows no FERPA, COPPA, GDPR, hosting or minimum-age declaration, and Diffit does not hold an independent 9ine assessment. Its privacy policy is the document to read before a district adopts it. Since the tool works on text rather than rosters, a substitute can use it without touching student data at all: paste the passage, not the class.
Best for a room with no working devices: Flip Education
Flip Education is the best fit for the period when the Chromebook cart is locked, the wifi is out, or you were told not to hand out devices, because every lesson it produces is designed to run on paper.
You enter a topic and a grade and it returns a printable lesson built around one of 64 active-learning formats: a debate, a simulation, a mock trial. The pack includes a teacher briefing, student cards and a facilitation guide, so it tells you what to say and when. For a substitute who does not know the class, a structured activity with defined roles is worth more than a worksheet, and it is a great deal easier to manage.
Its most useful property for this job is administrative rather than pedagogical: you can try five lessons with no login at all, and students never create accounts or touch a device, so there is no student data anywhere in the workflow.
Watch out for: printing. A screen-free lesson needs a working printer and a few minutes you may not have on a same-morning call. Generate and print the night before if you know your assignment, or ask the front office to run the pack while you take attendance.
Pricing: 5 free lessons with full curriculum access, no credit card and no time limit; Single Subject $7.99 a month, Multi-Subject $14.99, All Subjects $21.99, with 25% off annual billing; schools of 20 to 99 teachers pay $149 per teacher per year and districts of 100+ pay $119 (Flip Education pricing, checked September 10, 2026).
Safety: Flip Education declares GDPR compliance, hosts data in the US, states it does not collect student data, and honors deletion requests. Its minimum age is 18+, which is consistent with a teacher-facing tool: students never log in. FERPA and COPPA are recorded as not applicable, which follows from collecting no student data, though a district should confirm that against the privacy policy before adopting it. It does not hold an independent 9ine assessment.
Best for the all-purpose toolkit: MagicSchool
MagicSchool is the best fit as the one account to open if you only open one, because its free tier covers 80+ separate teacher tools rather than a single job.
For a substitute the useful ones are unglamorous: a quick exit ticket, a bell-ringer, a behavior-neutral note to leave for the returning teacher, a two-minute explanation of a concept you half remember. It is the tool you reach for when the need is small and unpredictable, which describes most of a substitute's day.
Against Knowt, MagicSchool is broader and shallower: more jobs covered, less purpose-built for any one of them. Directory readers rate it 4.74 from 19 reviews.
Watch out for: the free plan caps generations. MagicSchool's pricing page lists "unlimited generations" as a Plus feature, which means Free is limited, and the page does not publish the number. On a heavy day you may hit a wall you did not know was there.
Pricing: Free plan at "$0 Forever Free" with 80+ teacher tools, the Raina chatbot and quizzes; Plus at $8.33 per user per month billed annually or $12.99 monthly; Enterprise is custom, and it is the tier that carries the custom data privacy agreement and SSO (MagicSchool pricing, checked September 10, 2026).
Safety: MagicSchool's privacy policy states that "MagicSchool does not use personal information to train artificial intelligence or machine learning models," that its AI providers are "contractually prohibited" from doing so, and that data sent through AI APIs is "deleted within thirty (30) days." It processes data under FERPA where applicable "only for legitimate educational interests." Note the boundary quoted earlier: that policy does not cover processing done on a school's behalf, which is governed by the district's own agreement. Our directory record carries no FERPA, COPPA or hosting declaration. It holds an independent 9ine assessment.
Best for teaching content you never studied: Perplexity
Perplexity is the best fit for the assignment outside your subject because it answers with citations attached, so you can check the claim before you say it out loud to 30 teenagers.
This is not a hypothetical problem for substitutes; it is the job description. California's Emergency 30-Day Substitute Teaching Permit authorizes the holder to "serve as a day-to-day substitute teacher in any classroom, including preschool, kindergarten, and grades 1-12 inclusive," and requires a bachelor's degree in any field with no subject-matter competence test. An English graduate can be legally and routinely placed in a chemistry room. Nationally, 74% of public schools reported difficulty filling one or more vacant teaching positions with a fully certified teacher, according to the US Department of Education's School Pulse Panel of 1,392 schools surveyed August 13 to 27, 2024. Short-staffed buildings move substitutes across subjects.
What sets Perplexity apart from asking a general chatbot is that every claim arrives with a link. You are not trusting the machine; you are being handed a source to glance at. That is the difference between reading a fact aloud and repeating a guess. Directory readers rate it 4.27 from 15 reviews.
Watch out for: it summarizes whatever it finds, and it will sometimes find a weak page. Open the citation before you teach the point. Treat the answer as a starting draft, which is how any of this should be treated.
Pricing: free tier available; Perplexity's paid pricing could not be confirmed from the company's own pages during this check, so treat any figure you see quoted elsewhere as unverified (checked September 10, 2026).
Safety: our directory record shows no FERPA, COPPA, GDPR, hosting or minimum-age declaration for Perplexity, which is a general consumer product rather than a school tool. It holds an independent 9ine assessment. Use it for your own preparation, not as something you put in front of students, and keep student information out of your queries.
The big names AI assistants keep suggesting
Ask ChatGPT or Gemini for substitute teacher tools and four names come back. Short verdicts:
Khanmigo is built for sustained instruction with a class you know over weeks. A substitute covering one period is the wrong shape for it.
Quizlet is genuinely useful for a review period if the teacher already has sets, and useless if they do not, since building one from scratch costs more time than you have.
ChatGPT does everything the tools above do, less well and with no education-specific guardrails, and its consumer terms are consumer terms. It is a reasonable fallback when you have no account anywhere else.
NotebookLM is the best of the four for a long-term substitute assignment: load the unit materials once and interrogate them all semester. For a one-day placement it is more setup than the day is worth.
How to actually choose
Four questions, in this order, get you to the right tool in under a minute.
Did the teacher leave materials? If yes, work them rather than replacing them. That is Brisk if they are digital, Diffit if the level is wrong. Replacing a plan a teacher left is not your call to make.
If not, do you have a working device for every student? If no, Flip Education, and stop reading. A screen-free structured activity is the only thing that reliably works in a room with no devices.
Is the subject inside your training? If no, Perplexity first for your own understanding, then a tool to build the task. Never generate a lesson on content you cannot evaluate; you will not catch what it gets wrong.
Is this one period or one semester? A single period wants Knowt's timed agenda. A long-term placement is worth the setup cost of NotebookLM and a district conversation about a proper account.
Underneath all four sits the same rule: outsource the doing, not the thinking. These tools will write the agenda, level the passage and produce the printable pack. Deciding whether the class is ready for the activity, reading the room in the first four minutes, and choosing what to leave in the note for the returning teacher are yours, and no tool here has the information to do them.
What I'd do before your next assignment
Open two accounts tonight, on your own device, with your personal email: Knowt and one of Brisk or Flip Education, depending on whether your placements usually give you devices. Generate one plan for the grade band you get called for most and print it. That is your emergency pack, and it works on the morning you get a 6:40am call for a subject you were not expecting.
Then ask the building administrator one question at your next assignment: does the district have a licensed account a substitute can be added to? Some do. It takes ten seconds to ask, and it moves you inside the contract that all of this depends on.
The bottom line
For a substitute, the right tool is the one that runs from a personal account and never sees a student's name: Knowt for the plan, Brisk for materials already on the screen, Diffit for the wrong reading level, Flip Education for a room with no devices, MagicSchool for the rest, Perplexity for the subject you never studied. Compare the full pool in the AI Educator directory. The tools cover the paperwork. The judgment in the room is still the job, and it is the part they hired you for.
Dan Fitzpatrick is a Forbes contributor, three-time bestselling author and founder of The AI Educator, and has trained more than 150,000 educators across 30+ countries. Read more from Dan.
