The PreList VS Diffyn

The PreList's answer

The PreList is a workspace, not a point tool. Everything a screenwriter does between finishing a draft and submitting it happens in one place: analysis, reader feedback, the rewrite itself, and choosing where to send it.

Four things make it distinctive.

It measures as well as interprets. Alongside a coverage-style read across 11 core metrics and 51 subcriteria, a deterministic engine measures what is literally on the page: scene counts, dialogue share, INT/EXT and DAY/NIGHT balance, timeline, formatting. You see the measured facts beside the reader's interpretation, so structural problems are separable from matters of taste.

It gives you a room, not a verdict. Six reader personas each respond in their own voice with their own bias and their own blind spots, then a moderator synthesises where they agree and where they split. You can push back on any of them in conversation.

It includes a real screenplay editor, free on every plan, with clean unwatermarked PDF, Final Draft and Fountain exports. Your notes sit in the margin while you rewrite, and you can re-analyse the new draft against the old one without leaving the page.

It is willing to tell you not to spend money. The competitions directory carries verified deadlines and honest editorial verdicts on which contests are actually worth entering, and several free tools answer that question without an account.

Your scripts stay private, timestamped and owned by you. They are never used to train AI.

Diffyn's answer:

Addresses workflow and change management on LLM prompts, provide teams with traceability and visualization of tests across multiple models, provide deeper understading into efficiency of these prompts.

The PreList's answer

Most screenwriting tools do one thing: coverage, or a contest database, or an editor. The PreList is the whole loop in one workspace, so the notes, the rewrite and the submission all happen in the same place.

Three things genuinely set it apart.

First, the analysis is not only an opinion. Alongside a coverage-style read across 11 core metrics and 51 subcriteria, we deterministically measure what is actually on the page: scene counts, dialogue share, INT/EXT and DAY/NIGHT balance, timeline, formatting. You see the measured facts sitting next to the reader's interpretation, so you can tell the difference between a hard structural problem and a matter of taste.

Second, a proper screenplay editor is included free on every plan, with clean, unwatermarked PDF, Final Draft and Fountain exports. Revising does not mean exporting your script to a second app and losing your notes.

Third, when you upload a revision you get a like-for-like comparison against the previous draft: what changed, and why the score moved.

Add a verified directory of 115 competitions, programmes, fellowships and labs with tracked deadlines and honest verdicts on which are worth entering, and the price is £9.99 a month with a permanently free tier. One human coverage report usually costs several times that, and takes a fortnight.

Diffyn's answer:

Diffyn is the platform that specializes on both change management and multi-model analysis.

Diffyn's answer:

React, Next.js, POSTGRESQL

The PreList's answer

Screenwriters who are serious about the work but not yet resourced by the industry. Mostly feature and TV writers who are pre-representation or early in their careers, with a finished or near-finished draft, entering competitions, fellowships and labs, or preparing to send a script to a manager, producer or paid reader.

They all share the same problem. Professional coverage is expensive and slow, competition entry fees add up quickly, and both usually arrive after the money has already been spent. The PreList is the step before that: pressure-test the draft yourself, fix what is fixable, then spend on the human reader or the entry fee with a script that is actually ready.

Secondary audiences are script consultants, screenwriting educators and course leaders who use it alongside their own notes.

Diffyn's answer:

Professionals incorporating LLMs or AI tools in their workflow and wants to keep track of changes and test their prompts.

The PreList's answer

The PreList began with a frustration familiar to anyone who has finished a draft: the feedback loop is expensive, slow and inconsistent. Professional coverage runs into the hundreds and takes a week or two, and often tells you something you could have caught yourself. Competition entry fees compound it, because you pay them before you find out whether the script was ready.

Then in 2025 several of the platforms writers had leaned on for script hosting, coverage and contest discovery shut down, and a lot of that infrastructure simply vanished.

The PreList was built to fill that gap: somewhere to test a screenplay properly before spending money on a reader or an entry fee. It started as an analysis engine and grew outwards into the workspace around it, adding a panel of reader personas, a real screenplay editor, a verified competitions directory, and draft-over-draft comparison so you can prove a rewrite worked.

The name is the point. It is the work you do before your script goes on anybody's list.

It is built and run in London by THE PRELIST LTD, an independent UK company, and ships new features most weeks.

Diffyn's answer:

I started working on Diffyn when I notice that prompting has become an essential part of work across many industries. While there are version control platofrms like github, they are not designed for just prompt management are can be overkill such applications, it is also not integrated natively with various LLMs and relevant tools for users to validate ideas and visualise results properly.

The PreList's answer

The PreList is a self-serve product used by individual screenwriters rather than by companies, so there are no enterprise logos to list. Scripts are private by default and we do not publish customer names without explicit consent.

The current user base breaks down roughly as follows:

• Individual feature and television screenwriters, mostly pre-representation
• Writers preparing submissions to competitions, fellowships and labs
• A founding cohort of 50 early members who joined before public launch and still use the product
• Script consultants and professional readers who use it alongside their own coverage work
• Screenwriting educators and course leaders