← All models DeepSeek V4 Pro editing test DeepSeek · Tested Oct 28, 2026 · 1m 20s · $0.09
Four checks All in one 55/90 caught
Grammar & spelling 39/45 Repetitions 3/15 Redundancy 4/15 Consistency 9/15 101 comments · 7 extra flags
DeepSeek V4 Pro caught 55 of 90 planted mistakes, tied 15th of 16 models tested. It was strongest on grammar and spelling (39 of 45) and missed most on repeated words (3 of 15). The 4 checks took 1m 20s and cost $0.09; asked for all of them in one prompt, it caught 43.
Every comment DeepSeek V4 Pro left on our 6,000-word test story, where it left it. Click a missed mistake to find it in the text. The checks come from icanwrite , a markdown editor for writers.
Missed · 35
Dangling modifier: the door didn't turn the key “Turning the key at last, the door opened” who, not whom: subject of 'was' “whom she guessed was the owner” any other shop: the bakery is on Wharf Street “longer than any shop on Wharf Street” Fragment: the survey has no verb “The survey from twelve years ago, which an engineer from the county” in to, not into “turned his uniform into the quartermaster” 'one of those who' takes a plural verb: were “one of the last binders in New England who was still” Close: tired … tired “thin, tired ring” Distinctive, chapters apart: pewter “Pewter light from the tall back window” Distinctive, chapters apart: threadbare “a threadbare, flour-dusted sweater” Close: silence … silent “The silence in the workshop” Distinctive, chapters apart: meticulous “His records were meticulous” Close: neatly … neat “neatly labeled” Distinctive, chapters apart: gleaming “a gleaming pair of shoes” Distinctive, chapters apart: sodden “carrying sodden leaves” Close: whispered … whispered “he whispered, as if it were a secret” Distinctive, chapters apart: brittle “a short, brittle sound” Distinctive, chapters apart: stubbornly “which stuck stubbornly” Close: remembered … memory “her hands remembered” a.m. is the morning “ten a.m. in the morning” twins are two “the two twins” the reason … was because “was because he had never paid himself” a sum is a total “The sum total” an agreement is mutual “By mutual agreement” kept quiet = said nothing “kept quiet, saying nothing” planning is in advance “no advance planning” a haven is safe “a safe haven” began is first “the week we first began” join together “wants them to join together” an outcome is final “The final outcome” The bakery has three tables; she sits at the fourth “three small tables” Funeral in February, death in March “had died in March” The ledger: green, then red “a ledger bound in green leather” Tea becomes coffee “poured her a mug of tea” Tomas beside him: two decades, then thirty years “for most of two decades” The bakery: two doors down, then a ten-minute walk “BAKERY TWO DOORS DOWN”