Grammarly vs QuillBot vs Walter Writes AI: free tiers only

Stated figures first, because two of the three publish one and one does not. QuillBot's 125 words per input has no stated cap on the number of inputs, read 9 November 2026, so a writer who is willing to paste a paragraph at a time has no published monthly ceiling. Walter's 300 words is the whole allowance, checked 8 November 2026. Grammarly's 100 AI prompts a month is a published figure for the free account, read 9 November 2026, and the pages read do not say how many words a prompt carries or whether the free product-page tool draws on the 100 at all, so its word column is empty rather than estimated.

All read on the dates above. On the arithmetic QuillBot is the only free tier of the three that can take a full essay at all, and it takes one in twelve pieces. Splitting matters: each piece is rewritten without sight of the others, so terms, names and tense can drift between pieces and the joins are the writer's job afterwards. The free tier that takes a 1,500-word essay whole belongs to none of these three; Clever AI Humanizer accepts 3,000 words per request with no sign-up, checked 8 November 2026, and is compared with Walter in Clever AI Humanizer vs Walter Writes AI.

A different question from volume, and Walter wins it. Walter's trial runs the same three rewrite strengths as the paid plans, Simple, Standard and Enhanced, read 9 November 2026, so 300 words is enough to see the strongest mode on one paragraph before paying. QuillBot's free plan holds its stronger mode, Advanced, to 3 uses, read 9 November 2026, which is enough to see it and not enough to use it. Grammarly's free account carries all four preset voices and the custom voice, read 9 November 2026, which is the full setting range, with the vendor describing the paid version of the Humanizer as the full one without stating what the free one lacks.

All read on the dates above. The published method runs free tiers separately for the free ranking where the free limit accepts the input, and the protocol's inputs run 350 to 500 words. On the figures read, none of these three free tiers takes a protocol input whole: QuillBot's row is split by design, Walter's trial is 50 words short of the shortest input, and Grammarly's row depends on a cap the vendor does not print. Those rows, when a run is published, land on the free ranking rather than here.

A rewrite is a paraphrase whatever it costs. Weber-Wulff and colleagues tested 14 AI text detectors and found every one below 80 percent accuracy, with accuracy falling further on paraphrased and machine-translated text (Weber-Wulff et al. 2023, International Journal for Educational Integrity, read 9 November 2026). Liang and colleagues found that seven GPT detectors flagged 61.3 percent of TOEFL essays by non-native English writers as AI-generated (Liang et al. 2023, Patterns, read 9 November 2026), which is the reason a light rewrite that lowers a reading may be fixing a false positive rather than hiding anything.

Grammarly is the one vendor of the three that states the point outright: its product page says the humanizer is not intended to get past AI detectors and works on clarity instead, read 9 November 2026. QuillBot's page makes no detector statement; Walter ships a built-in detector that scores its own output, which is not independent evidence. The method weights meaning kept at 35 points of 100 and detector pass rate at 30, so a free tier that keeps every claim beats one that lowers a reading by changing what a sentence says. No detector score should be the only evidence in a misconduct case.