DeepSeek grammar checker

This DeepSeek grammar checker is a diagnostic route. It resolves to a server-side classifier whose instruction is to analyse the submitted text and report findings, which means the output is a written account of the grammatical and clarity defects located in your text. It is not a correction route and does not return an amended document.

The distinction is worth stating because the search term conflates two products. Checkers report; fixers substitute. A reader who wants substituted text is served by the rewriter routes on this site, which operate under a different engine instruction. Constraints here: text is transmitted to our server, 12,000 characters per request, five requests per rolling 24-hour window, no account and no paid tier.

Two layers, and the second is where a reviewed AI draft usually fails.

Concord and tense

Subject-verb disagreement and unmotivated tense shifts within a passage.

Sentence boundary errors

Comma splices, fused sentences and unintended fragments.

Attachment errors

Dangling and misplaced modifiers, where the syntax attaches a phrase to the wrong noun.

Punctuation

Apostrophe use, semicolon misuse in place of a comma, and quotation punctuation.

Voice and agency

Passive constructions that suppress the actor where the actor is material.

Structural clarity

Clause stacking, sentence length without variation, and diction more complex than the proposition requires.

Beyond the cap, segment on section boundaries. Each segment consumes one request from the allowance.

Step 1

Submit the passage, under 12,000 characters.

Step 2

Optionally narrow the analysis through the instruction field.

Step 3

Apply the findings selectively, then re-read the passage as a whole.

A near-empty correctness report on model-generated prose is the expected result rather than evidence of a failed check. Surface grammaticality is the property current language models satisfy most reliably, because it is the most densely represented regularity in their training distribution.

The defects that remain sit above the sentence: uniform clause length, metatextual paragraph openers, hedging before assertion, and connectives substituting for inferential links. These are clarity findings, not grammatical ones, and they are the section of the report worth reading closely on a DeepSeek draft. A checker that reported only concord errors would report nothing useful about such a text.

One optional field, 300 characters, appended to the engine instruction. No dialect selector, no register control, no strictness parameter, no document-type classification. Those interfaces exist on competing pages because those products have settings; this request carries a route, a family, the text and one optional string.

The field rewards specificity. A constraint expressed as a condition, such as naming the target dialect or restricting the analysis to one defect class, is honoured far more consistently than an abstract direction about quality. Narrow instructions produce narrow, usable reports.

Each omission below corresponds to a capability the route does not have. Competing pages supply several of them.

A 0 to 100 grammar score

The engine emits prose. A numeral derived from prose would assert a calibration that was never computed.

Defect counts by category

Findings are named, not tallied, because the output is not a structured record.

Readability and CEFR levels

No such metric is calculated on this route. Presenting one would be invention.

Inline markup

Character offsets are not returned, so the original cannot be annotated in place.

Continuous checking

This is a discrete request, not a resident service or browser extension.

A language coverage claim

Per-language behaviour has not been tested here, so no list and no count is offered.

Two error modes, in opposite directions. It omits defects, particularly in long passages where attention thins toward the middle. It also flags correct constructions: deliberate fragments, dialectal forms, technical register, domain conventions and quoted material all attract spurious findings because they deviate from the norm without being errors.

A structural limitation deserves separate mention. Grammatical well-formedness is orthogonal to factual accuracy. A false date, a transposed figure or a misspelled proper noun sitting inside a well-formed clause produces no finding at all, because nothing about the syntax is defective. Verification of content remains outside this route entirely.

Writers at the final pass, where the argument is fixed and only the prose is in play. Second-language writers who want the defect named and explained rather than silently replaced. Reviewers who need an account of what is wrong with a submission they did not write.

It is the wrong instrument mid-draft, where line edits will be discarded in the next restructure, and for anyone whose actual requirement is corrected output rather than a diagnosis.