Diffit vs Twee: Which Works Better for English Teachers?

Diffit and Twee overlap more than most tool pairs, but they split cleanly on one thing: Diffit levels an existing text into several reading versions for free, while Twee builds a whole lesson’s worth of material around CEFR levels for a fee. Choose Diffit for differentiation, Twee for production.

Key takeaways

• Diffit’s free tier is genuinely unlimited for core generation. Twee’s is a 5 run trial. If cost is the deciding factor, this settles it.
• Only Twee works in CEFR. Diffit uses US reading levels, which is a real mismatch for international English teaching.
• Diffit does one job very well. Twee does many jobs across a lesson, from reading text to gap fill to assessment.
• Verified pricing on 19 September 2026: Diffit individual is 14.99 dollars a month or 149.99 a year. Twee Basic is 6.50 a month billed annually, Pro is 10.50.
• Diffit’s paywall is mostly about export format. Free users get PDF, paid users get Google Docs, Slides and Word.
• Twee is cheaper than Diffit at every paid tier, which surprises most people.

The one line answer

If you have a text and need it at three levels, use Diffit and pay nothing. If you have a topic and need a lesson, use Twee and pay for it.

Diffit vs Twee side by side

Compiled 19 September 2026 from each platform’s official pricing pages.

Where Diffit wins

The free tier is real. This is the strongest argument for Diffit and it is not close. Core generation is unlimited, with no credit card and no generation count. Most edtech free tiers are trials wearing a disguise. This one is not.

It is faster at its one job. Paste a URL, choose your levels, and get every version at once with comprehension questions and vocabulary attached. Twee can produce a levelled text too, but Diffit generates the variants simultaneously, which is the whole point when you have a mixed ability group.

Privacy is simpler. Diffit collects no student data at all, which makes the conversation with a school data protection officer very short.

It works from awkward sources. URLs, PDFs and video, not just typed topics.

Where Twee wins

CEFR, natively. Diffit thinks in US grade reading levels. If you teach a B1 class in Spain or an A2 group online, you are translating between systems every time, and the mapping is approximate at best. Twee just asks which CEFR level you want.

Breadth within the lesson. Diffit gives you a text, questions and vocabulary. Twee gives you those plus dialogues, gap fills, discussion prompts, lead in activities, listening work and assessment, all from the same source.

It is cheaper. This catches people out. Twee Pro at 10.50 dollars a month billed annually undercuts Diffit’s individual plan at 14.99, while covering considerably more ground.

Export is included. Twee exports to PDF, Word, Google Docs and Google Forms on the paid plans. Diffit reserves Google and Word export for paying users and gives free users PDF only.

The reading level problem, in detail

This is the part most comparisons skip, and it matters more than any feature list.

Diffit levels text by US grade reading level, which measures reading ability in a first language English speaker. CEFR measures language proficiency in a second language learner. They are not the same axis. A text pitched at a US fifth grader can contain idiom and cultural assumption that an adult B2 learner finds harder than a text two grades above it.

In practice Diffit output still works for ESL, and plenty of teachers use it happily. But you are eyeballing the fit rather than setting it, and you will occasionally be wrong in ways that only show up in class. Our guide to Diffit for teachers goes into where this bites hardest.

Who should pick which

Pick Diffit if your classes are mixed ability and your main task is making one text accessible to everyone, if you have no budget, or if you teach within a US school system where grade levels are the working currency.

Pick Twee if you teach in CEFR terms, if you build materials from scratch rather than adapting existing ones, or if you want exercises and assessment as well as text.

Use both if you can. Diffit free costs nothing and handles differentiation. Twee Pro at 10.50 a month handles production. Together that is cheaper than a Diffit individual subscription alone.

A fair test before you decide

Take one real lesson you have to teach next week. Run it through both. Not a demo topic, an actual class with an actual level.

With Diffit, check whether the levelled output suits your learners or whether you are mentally adjusting for the grade to CEFR gap. With Twee, check whether the five trial runs get you something you would genuinely put in front of a class.

That test takes half an hour and tells you more than any comparison table, including this one.

Read further

Full detail in the Twee review for English teachers and in What is Diffit?. If neither fits, see Twee vs MagicSchool or the wider guide to the best AI tools for English teachers.

You can also try our free Lesson Plan Generator, which builds a CEFR levelled ESL lesson with no account wall, and read the wider guide to AI in English language teaching.

Frequently asked questions

Is Diffit or Twee better for ESL teaching?

Twee, if you work in CEFR terms. It treats language level as a native setting while Diffit uses US grade reading levels, which measure first language reading ability rather than second language proficiency. Diffit is still useful for ESL, but you are estimating the fit.

Which one is free?

Diffit, meaningfully. Its free tier gives unlimited core generation with PDF export and no credit card. Twee’s free tier is a 5 run trial intended for evaluation rather than teaching.

Which is cheaper to subscribe to?

Twee. Basic is 6.50 dollars a month billed annually and Pro is 10.50, against Diffit’s individual plan at 14.99 a month or 149.99 a year. Twee also covers a wider range of tasks at that price.

Can Diffit generate exercises as well as reading texts?

Yes, but a narrower range. Diffit produces comprehension questions, vocabulary lists and graphic organisers alongside the levelled passage. Twee offers more than 40 tools covering gap fills, dialogues, discussion questions and assessment.

Do I have to choose between them?

No, and the combination is often the best value. Diffit free handles differentiating existing texts while Twee Pro handles building new material. At 10.50 dollars a month total that costs less than subscribing to Diffit alone.

Does Diffit support CEFR levels?

Not directly. It works in US reading levels, roughly second grade through high school. There is no CEFR setting, so matching output to A2 or B1 means judging it yourself rather than selecting it.