Cotypist vs Slopsift

Cotypist and Slopsift are both grammar & style checkers tracked by AIDiveForge. Below is a side-by-side comparison of pricing, capabilities, platforms, and ownership — sourced from each tool's live website and verified before publishing.

Cotypist

Cotypist sits in the macOS menu bar and surfaces word-completion suggestions as you type, accepted with a Tab keystroke, across whichever apps you have open. The differentiating mechanic is per-app instruction profiles: you teach it one voice for client emails, a different register for pull-request descriptions, and it holds those rules separately per application. On-device processing keeps your keystrokes off external servers. The free tier caps daily output at 100 words — a ceiling that arrives fast for anyone with real writing volume. No API, no Windows build, no self-hosting path exists.

Slopsift

SlopSift builds a dependency graph per sentence using a 16 MiB quantized ONNX model that runs in Node or browser WebAssembly — no API call, no text upload, no remote judge. Rules inspect that graph for structural tells: the canned three-paragraph outline, the actorless passive hiding who made the decision, the certainty claim with no source. Output matches ESLint's JSON shape, so CI pipelines can consume findings without a custom parser. The ceiling appears when your linting needs go beyond the rule set the team has authored — there is no config surface described for writing custom rules, and the project is early enough that the documented rule count is small.

Attribute	Cotypist	Slopsift
Pricing	Paid	Free
Price	$6/mo or $9/mo	—
Free trial	30 days	No
Open source	No	Yes
Has API	No	No
Self-hosted option	No	Yes
Platforms	macOS	Browser, Node.js, CLI
Pros	Per-app instruction profiles let you maintain a different writing register for each application, so client emails, Slack messages, and code comments each get the voice you set without manual switching. On-device processing means your keystrokes and draft content are not transmitted to external servers, which matters for anyone working with confidential documents or under data-handling obligations. Tab-to-accept inline completions work inside whichever Mac app has focus, so you never break flow by switching to a separate chat window or sidebar. Multi-Mac profile sync at the paid tier means your per-app voice configuration carries across machines, avoiding the tedious work of reconfiguring from scratch on a second device.	Dependency-graph parsing instead of word matching, which means the linter catches canned argument structures and vague-attribution constructions that slip through any blocklist approach. 16 MiB quantized ONNX model runs fully on-device in Node and browser WebAssembly, so a draft never leaves the machine — which means teams with data-handling restrictions can actually use it without a policy exception. ESLint-shaped JSON output, so CI pipelines and existing editor tooling can consume findings without a custom integration layer. Three-tier severity grading (error / warning / note) keeps the writer in the loop on close calls rather than collapsing everything to a binary flag — which means the linter surfaces candidates for review instead of making editorial decisions it cannot defend. Open-source with self-hosted and browser execution paths, which means no vendor dependency and no runtime cost as document volume scales.
Cons	The free tier's 100-words-per-day cap cuts off mid-session for anyone with real writing volume — a journalist drafting a single article, a developer writing commit messages all morning, or a support agent handling a ticket queue will exhaust it before noon and face a choice between upgrading or stopping. There is no Windows version, no Linux path, and no browser extension, so any team that runs a mixed OS environment cannot standardize on this tool — the realistic next step is a browser-based assistant like a Chrome extension that works across platforms. No API means completions cannot be scripted into a build pipeline, a CMS workflow, or any automated process — teams that want completion suggestions integrated into custom tooling have no integration surface and will need a provider that exposes one. The passive suggestion model offers no ability to run multi-step tasks, draft from a prompt, or trigger actions — writers who need to generate a full first draft rather than complete sentences in progress will find the interaction model too narrow and reach for a dedicated generation tool.	The documented rule set covers a fixed set of structural tells. Teams whose specific style problems — say, detecting hedging patterns specific to their domain or enforcing house argument structure — fall outside that set have no documented path to author custom rules. The next move is either forking the repo or staying with a more configurable linting framework. No API and no hosted tier means every environment that needs linting — local machines, CI runners, agent runtimes — must install and run the Node package independently. Teams used to a single hosted endpoint for all surfaces will be managing per-environment installs. The project is early-stage and the rule count is small relative to the full surface of AI writing patterns. Teams needing coverage across a broad, heterogeneous document corpus will hit gaps quickly and are more likely to end up on a general-purpose grammar or style linter that offers a wider plugin ecosystem.

Bottom line

Cotypist is paid while Slopsift is free; Slopsift is open source. Choose based on which difference matters most for your workflow.

Frequently asked questions

What is the difference between Cotypist and Slopsift?

Cotypist is Paid, while Slopsift is Free and open source. Compare pricing, free trial, API, platforms, and pros/cons in the table above on AIDiveForge.

Is Cotypist better than Slopsift?

It depends on your workflow. Use the side-by-side attributes (pricing, open source, API, self-hosted, platforms) to decide. AIDiveForge does not rank a universal winner — we publish verified facts so you can choose.