QuillBot Review (2026): Pricing, Limits and Best Alternative

QuillBot is an AI writing suite that started as a paraphrasing tool and now bundles an AI detector, an AI humanizer, a grammar checker and a plagiarism checker. The verdict of this QuillBot review: it covers a lot of ground, but the free tier is tight, refunds are limited and its humanizer isn't built to get past AI detectors.

Our top pick is Essai. In our view, it is the best AI humanizer and the best AI detector for students and writers in 2026. Essai combines an AI humanizer designed to keep your meaning while making your writing read naturally with a free AI detector, so you can revise a draft and check it in one workflow.

This review is based on QuillBot's pricing page, product pages, help center and Trust Center as of October 2026, along with the RAID benchmark leaderboard, QuillBot's Trustpilot page and published research on AI detection.

QuillBot at a glance

Pros and cons

Pros

• Many tools in one plan. Premium covers the full paraphraser, advanced grammar suggestions, AI humanizer, AI detector, plagiarism checker and summarizer, according to QuillBot's pricing page.
• Low price on annual billing. Premium costs $99.95 a year, which works out to $8.33 a month, as of October 2026.
• A free detector with highlights. Free users get an AI likelihood score from 0 to 100% with the flagged sentences highlighted.

Cons

• A humanizer that isn't meant to pass AI detectors. QuillBot's humanizer page says the tool "isn't a tool for evading AI detection," and a help center article says it "does not try to trick AI detectors or promise undetectability."
• Tight free limits. Free humanizing stops at 100 words with "limited usage," and the detector page caps free scans at 1,200 words each and six a day.
• Mixed messages on the free detector. A help center article updated in June 2026 says bulk file upload is the only Premium difference, which contradicts the caps on the detector page.
• No free plagiarism checks. The plagiarism checker is Premium-only, capped at 25,000 words a month, and QuillBot's own FAQ says it cannot detect paraphrased content.
• Limited refunds. QuillBot's help center says refunds are issued only if required by law, and unexpected auto-renewal charges are a frequent theme in recent one-star Trustpilot reviews.
• Your text may train its AI. QuillBot's Trust Center says user inputs are used to train and personalize its services, with opt-out controls for browser extension users.
• A headline accuracy figure that needs context. The 99% claim rests on a RAID leaderboard entry QuillBot submitted in January 2025, scored against texts from older AI models.

Key features

QuillBot covers a lot of ground, but nearly every tool has a free cap, and the two that matter most for AI-assisted writing come with fine print.

AI detector

The QuillBot AI detector needs at least 80 words of pasted text and returns a 0 to 100% likelihood that the text was AI-generated. Flagged sentences are highlighted, and "explainer cards" describe why a passage looks machine-written. QuillBot says texts of 300 words or more give more reliable scores and that the detector covers 20+ languages.

The limits: free users get up to 1,200 words per scan, six scans a day and a single explainer card. Premium lifts the caps, adds explainer cards across the full text, lets you download and share reports and accepts batch uploads of up to 20 files. Real-time detection inside QuillBot's AI chat and browser extensions is still labeled "coming soon."

AI humanizer

The QuillBot humanizer smooths stiff, repetitive AI wording, and QuillBot says it keeps your original meaning. It offers Standard, Academic, Professional and Casual modes in five languages: English, Spanish, French, German and Portuguese. Free use stops at 100 words with limited usage. Premium removes the cap and adds tone insights, a rewrite history and humanizing inside ChatGPT and Gemini through the browser extension.

The bigger catch is the tool's goal. QuillBot says its humanizer isn't meant for evading AI detection, so if you need AI-assisted text to read as human-written when it is checked, you are working against the tool's design. Essai's humanizer is built for that job: it is designed to keep your meaning while making phrasing, rhythm and word choice read naturally, and to help text pass popular AI detectors. If you use AI for coursework, check your course's AI policy first.

Paraphraser and grammar checker

The paraphraser is QuillBot's original product. Free users can rephrase up to 100 words in two modes, Standard and Fluency, while Premium removes the limit and adds nine built-in modes plus custom ones. Paraphrasing works in 23 languages. The grammar checker covers six languages on both plans, and Premium adds advanced suggestions and tone insights.

Plagiarism checker and extras

The plagiarism checker is Premium-only. It scans up to 25,000 words a month, and extra words cost $2.45 for 6,250, $8.95 for 25,000 or $19.95 for 62,500, as of October 2026. QuillBot names Copyleaks as its third-party vendor, and its own FAQ says the checker cannot detect paraphrased content. The suite also includes a summarizer (1,200 words free, 6,000 on Premium), a translator, a citation generator and AI chat.

QuillBot pricing (as of October 2026)

QuillBot sells one individual plan, Premium, with four billing periods, plus a Team Plan for groups. Prices below are the default US-dollar rates on QuillBot's pricing page and its Team Plan page.

Before you pay, note these rules:

• Checkout prices can vary. The pricing page's embedded data also lists other price points, such as monthly rates up to $24.95, so confirm the amount you see before paying.
• Auto-renewal. Premium renews unless you turn off auto-renewal, which you can do at any time while keeping Premium until the billing period ends, according to QuillBot's cancellation article.
• Refunds. In a help center article updated in March 2026, QuillBot says refunds are issued only if required by law, and app-store purchases go through Apple or Google.
• Team seats. A seat costs $89.95 a year for 2 to 10 users, $79.95 for 11 to 50 and $69.95 for 51 or more, as of October 2026.

How Essai compares: on month-to-month billing, Essai Basic costs $14.99 against $19.95 for QuillBot Premium, as of October 2026, and every Essai paid plan includes unlimited AI detection. Essai's free tiers are also more generous for humanizing and checking: 125 humanizer words per request with no signup or credit card, against QuillBot's 100, and unlimited detector scans with a free account instead of six a day. Compare all three plans on the Essai pricing page.

Is QuillBot accurate?

QuillBot backs its detector with a benchmark result, and it is frank about where detection breaks down. Here is what the company claims, what the headline number actually measures and what research says about tools like it.

What QuillBot claims

The AI detector page promises a "99% detection rate" and credits it to evaluations from RAID, and its FAQ says RAID covers ChatGPT, GPT-4, GPT-5, Claude, Gemini, Mistral, Llama and more. QuillBot adds that when a result is unclear, its model "tends to classify texts as human written."

The same page lists real limits. QuillBot says no AI detector can be perfectly accurate, that heavily paraphrased or lightly AI-edited text is harder to catch, and that formulaic human writing such as academic definitions, legal copy and templates "can score higher than expected." It also tells educators never to rely on a detector score alone when a student's standing or someone's career is at stake.

What the 99% figure measures

RAID is a public benchmark for AI text detectors, introduced in an ACL 2024 paper. Under its submission rules, detector makers run their own tool on RAID's test set, whose answer labels are hidden, and RAID scores the predictions they send in. QuillBot's entry is dated January 30, 2025.

Four caveats apply:

• The cutoff allows false positives. RAID sets a threshold in each domain so that 5% (or 1%) of human-written texts get flagged, then measures how much AI text is caught. A 99% figure is a catch rate at that setting, not a promise that human writing is never flagged.
• The AI texts come from older models. RAID's documentation lists 11 generators, including GPT-2, GPT-3, ChatGPT, GPT-4, Llama 2, Mistral 7B, MPT-30B and Cohere models. It does not list Claude, Gemini or GPT-5, which QuillBot's FAQ mentions.
• Attacks cut into the score. At the stricter 1% setting, the entry's weakest results came on texts with zero-width spaces inserted (91.4%) and on paraphrased texts (94.1%).
• It is a snapshot. The entry reflects the detector QuillBot submitted in January 2025. QuillBot says it retrains its models regularly, so today's tool may score differently in either direction.

What research says about AI detectors

QuillBot was not part of the following studies, but they show how detectors in this category can fail:

• Bias against non-native writers. In a 2023 study published in Patterns, Liang and colleagues ran 91 TOEFL essays by non-native English writers through seven popular detectors. The detectors misclassified more than half of them as AI-generated (an average false-positive rate of 61.22%), and 89 of the 91 were flagged by at least one detector. One tool in that study, AI Writing Check from Quill.org and CommonLit, is unrelated to QuillBot.
• OpenAI retired its own classifier. OpenAI withdrew its AI text classifier on July 20, 2023, citing its "low rate of accuracy." OpenAI's evaluation found it caught 26% of AI-written text and labeled human text as AI 9% of the time.
• Small error rates add up. Turnitin says it aims for a false-positive rate below 1% but that the rate "is not zero." Vanderbilt University disabled Turnitin's AI detector in August 2023, noting that a 1% rate across the 75,000 papers it submitted in 2022 could have meant around 750 wrongly labeled papers.

Why false positives happen

QuillBot explains that detectors look at how predictable a text is, how much its sentence structure varies and how repetitive it is. Careful human writing can share those traits, especially when it is short, formal or follows a template. Liang's team found that the essays every detector flagged had significantly lower perplexity, which means a language model found them more predictable.

So read a QuillBot score as one signal among several. If your own writing gets flagged, keep your drafts and version history and ask how your school reviews AI concerns. Our guide to AI detection false positives covers next steps, and teachers can follow a fair process for checking student essays for AI.

Where Essai's detector fits

Essai's free AI detector returns an AI probability score from 0 to 100% and works best on 150 words or more, and a free account adds detailed reports and unlimited scans. Because it sits next to the humanizer, you can rework a flagged passage and check it again without switching tools. In Essai's internal testing, our detector outperformed other AI detectors on many of the criteria we track.

What users say

On Trustpilot, QuillBot shows a TrustScore of 4.8 from 14,510 reviews as of October 16, 2026, though Trustpilot notes that the company "hasn't invited customers recently, so reviews may not be representative." Short five-star reviews praise time savings and easy use for school and work. Recent one-star reviews keep returning to the same few problems:

• Unexpected renewal charges. Many recent one-star reviews describe auto-renewal charges the reviewer did not expect, often followed by a refused refund.
• Humanized text still flagged. Some unhappy users say text they ran through the humanizer was still flagged as AI, and one says the detector flagged their own writing.
• App friction. A few reviewers dislike being pushed toward the app or find it harder to use than the website.

If you do subscribe, write down your renewal date and turn off auto-renewal if you only need Premium for a month or a term.

What Essai users say

Here is how Essai users describe the humanizer in their own words:

"I used to spend hours rewriting essays. Now Essai does it in seconds. The text humanizer is incredibly accurate and saves me so much time on every assignment." (Robert Kim, Essai user)

"The quality of the humanized text is remarkable. Essai preserves my ideas while making everything sound natural. My grades have improved significantly since I started using it." (Michael Foster, Essai user)

"I've tested many alternatives, but nothing comes close to the quality Essai provides." (Priya Sharma, Essai user)

QuillBot vs Essai

QuillBot spreads its effort across about a dozen writing tools. Essai focuses on the two that matter when you work with AI-assisted text, a humanizer and a detector, and builds them to work together. Here is how they compare on published facts as of October 2026.

Why Essai is the better QuillBot alternative

• A humanizer built for the job. QuillBot says its humanizer isn't meant for evading AI detection. Essai's humanizer is designed to keep your meaning while making phrasing, rhythm and word choice read naturally, so AI-assisted text reads as human-written, and to help it pass popular AI detectors.
• Humanize and check in one workflow. The humanizer and the detector live in the same app, so you can rework a draft and check its AI probability score without switching tools.
• More free humanizing. Essai's free tier takes up to 125 words per request with no signup or credit card, against QuillBot's 100 words with limited usage.
• Unlimited free detection. A free Essai account adds detailed reports and unlimited scans, while QuillBot's detector page caps free users at six scans a day.
• A lower monthly price. As of October 2026, Essai Basic costs $14.99 a month against $19.95 for QuillBot Premium on monthly billing, and every Essai paid plan includes unlimited AI detection.

Best QuillBot alternatives

Prices below are as of October 2026.

1. Essai: best overall. Our top pick for students and writers. It pairs an AI humanizer designed to keep your meaning with a free AI detector, starts free with no signup and costs $14.99 a month, or $9.99 a month billed yearly.
2. Grammarly AI Detector: best for Grammarly users. An all-round writing assistant with AI detection built in, but the free checker gives one overall score, flagged passages need Pro at $30 a month or $144 a year, and Grammarly says its humanizer "is not intended to bypass AI detectors."
3. Smodin: another all-in-one suite. It bundles an AI detector, humanizer, plagiarism checker and AI writer from $12.99 a month, or $10 a month billed annually, but every subscription is non-refundable and its accuracy figures change from page to page.
4. Undetectable AI: best for high word volumes. A humanizer with a free AI detector and plans priced by monthly word volume, from $5 a month billed yearly. Refunds are narrow, and most users can only cancel by email.
5. GPTZero: best for detection only. A dedicated detector with a free plan of 10,000 words a month but no humanizer. Paid plans start at $23.99 a month, or $12.99 a month billed annually.

For the full rankings, see our guides to the best AI humanizers and the best AI detectors.

QuillBot review: the verdict

QuillBot is a capable all-round writing toolkit, especially if you want paraphrasing and grammar help on an annual plan. For AI-assisted writing, though, it falls short where it counts: tight free limits, limited refunds, a headline accuracy figure built on a January 2025 benchmark entry, and a humanizer that QuillBot itself says isn't meant for getting past AI detectors. In our view, Essai is the best QuillBot alternative in 2026 and the smarter choice for students and writers, with a humanizer designed to keep your meaning while making your writing read naturally, a free AI detector in the same workflow, and paid plans from $14.99 a month, or $9.99 billed yearly, as of October 2026. Start free on up to 125 words per request, check the result and upgrade only when you need more words.