Guides · AI marking

AI marking tools for UK teachers, compared

There are now enough AI marking tools that choosing one is its own job. Most look similar on a landing page. They differ on a handful of design decisions that matter far more than the AI model underneath: whose mark scheme they use, what students have to sign up for, and how much of the checking they do for you.

Updated 9 October 2026 · 9 min read

We make Paddle, so read this with that in mind. Everything said about other tools below is taken from their own websites as of October 2026, and we have made no claims about anyone's accuracy. If something here is out of date, email hello@workpaddle.com and we will correct it.

The five questions that actually separate them

1. Whose mark scheme?

This is the biggest difference between tools, and it is a genuine trade-off rather than a right answer.

• Built-in exam board schemes. The tool has been set up in advance for specific boards and question types. You pick the question and it marks. Fast to start, and useful if your marking mostly mirrors exam questions. Less useful for a department's own scheme, a non-standard task, or anything outside the boards and questions covered.
• Your own scheme. You paste or upload the scheme you already use. More flexible, works for any subject, level or task, and keeps the standard your department agreed. It does mean the quality of the marking depends partly on the quality of the scheme; see how to write one that marks consistently.

2. Do students need accounts?

Some tools have students join a class with an account; others take submissions through a link with no sign-up. Accounts make rosters and tracking easier. They also create a set of child accounts the school is responsible for, which is often what a data protection officer asks about first.

3. Typed, handwritten, or both?

Mock exams are mostly handwritten. If that is what you want marked, check handwriting support specifically and test it on your students' real handwriting, not a neat sample.

4. Who approves the mark?

Every serious tool says the teacher stays in control. Look at what that means in practice: is every mark held until you release it, or are marks released by default with an option to review? Ofqual and JCQ are both clear that AI must not be the sole marker of qualification work, and the DfE expects teachers to apply professional judgement to AI output; see is AI marking allowed?

5. How much checking does it do for you?

All AI marking makes mistakes. The useful difference is whether a tool shows you where. Look for evidence you can verify (quotes from the student's own work), a confidence or uncertainty signal per mark, and some check that a score agrees with the level it claims. A tool that cannot show its working turns review into re-marking.

The tools

Paddle

Marks against the teacher's own scheme only; there is no template library. Students submit through one link without an account. Every criterion quotes the student's own words, and the quote is checked against the submitted text before the teacher sees it; every score is checked against its band; every mark carries a confidence score. Nothing reaches a student until the teacher publishes it. Students can resubmit an improved version. Student work is stored in the EU and not used for training. Free for 25 marks a month. Gaps worth knowing: typed work only, no handwriting yet, and no built-in exam board schemes, so you bring your own.

Marking.ai

The closest to Paddle in approach: it marks against the scheme you already use, students submit through a shared link, and each mark is a proposal until the teacher approves it. It handles handwritten as well as typed work and stores data in the EU. It has a one-off free allowance of 20 submissions, then monthly plans, with school licences on request.

TeachEdge

AI-assisted marking for KS3, GCSE and A-level, aligned to exam board standards (the boards covered vary by subject), for typed and handwritten work. At KS3 teachers set their own success criteria. Class marking uses student accounts joined by class code; quick marking and exam-script marking do not. Marks are held for teacher release by default. Monthly credit plans start from £5, with school and trust plans available.

GradeOrbit

Describes itself as a marking assistant rather than an auto-marker, with the teacher approving every grade. It offers its own GCSE English schemes for the major boards (written by GradeOrbit rather than the boards) or lets you use your own. Credit-based, with a free trial allowance.

Top Marks AI

A large set of marking tools (400+ across 40+ subjects), benchmarked to exam board standardisation materials and chosen by qualification, board and module. It is sold to schools and trusts rather than individual teachers, and is built around handwritten scripts: the teacher scans barcoded papers and uploads them, rather than students submitting.

CoGrader

Mainly aimed at US schools, with a rubric library and the option to upload your own rubric; it also offers GCSE marking. It has a free tier of 150 essays a month and school plans.

Graide

Describes itself as AI that learns with each input from the marker. It is aimed at further and higher education, vocational training and awarding bodies rather than schools.

ChatGPT and other chatbots

Free or cheap, flexible, and convincing on a single essay. Across a class set, general-purpose chatbots can drift, mark low and occasionally quote words the student never wrote, because nothing checks their output; and they raise data protection questions a dedicated tool is designed to answer. There is a full page on this.

How to choose in an afternoon

1. Shortlist by scheme. If you mostly mark exam-style questions for one board, try a built-in-scheme tool. If you mark your own tasks or department schemes, try an own-scheme tool. Try one of each if unsure.
2. Pick five scripts you have already marked, across the range.
3. Run them blind in each tool, without telling it your marks.
4. Compare the pattern, not the exact numbers: a mark or two either way is normal; a consistent lean is the thing to watch. The method is in how accurate is AI marking?
5. Time the review. How long did it take you to agree or correct each mark? That, not the marking speed, is the time you will actually save.
6. Ask the data questions before a class set goes in: where it is stored, whether it trains models, and whether the school can sign a data processing agreement.

Common questions