QuillBot vs Smodin in 2026: two overlapping detection-and-refinement suites, priced differently
Both bundle an AI writer, a plagiarism checker, an AI detector, and a humanizer into one subscription. The real differences show up in scale, language support, and what each considers its flagship feature.
QuillBot has 35 million users versus Smodin's reported one million-plus, a meaningfully larger user base and longer track record.
Smodin supports 100+ languages across its writer, detector, and humanizer; QuillBot's grammar checker is limited to 6 languages, though its plagiarism checker covers 100+.
QuillBot's paraphraser offers 9+ distinct modes plus a Custom mode on Premium; Smodin does not offer a comparable multi-mode paraphrasing tool, framing its AI writer more generally around essays, summaries, and chat.
Smodin's AI detector claims 99.8% accuracy with sub-2-second scans; QuillBot does not publish a comparable accuracy figure for its own AI Detector.
QuillBot Premium costs roughly $9.95/month billed annually; Smodin Premium starts from $14/month billed annually, with Smodin Starter at roughly $9/month as the closer price match.
Smodin offers a Chrome extension on Premium for in-browser detection and humanizing; QuillBot's Chrome extension is available on every tier including free, rated 4.7 across 6 million active users.
Neither tool has a public developer API in the way a dedicated integration platform would: QuillBot has none published, while Smodin's API is described as limited on Starter and extended on Premium without full documentation.
This is the closest head-to-head pairing in the category, because QuillBot and Smodin genuinely chase the same buyer with a similar stack: a paraphraser or AI writer, a grammar or humanizing layer, a plagiarism checker, and an AI detector, all in one subscription instead of four separate tools. QuillBot leans on 35 million users and a paraphrasing engine with 9+ distinct modes, built on Learneo's academic heritage alongside Course Hero and Scribbr. Smodin leans on over a million users and multilingual reach across 100+ languages, with detection and humanizing framed as the primary workflow rather than a secondary feature. Price is close too: QuillBot Premium runs about $9.95/month and Smodin Premium runs from $14/month, both billed annually.
The tools at a glance
QuillBot
All-in-one AI writing suite trusted by 35M+ writers for paraphrasing, grammar, plagiarism detection, and content creation
QuillBot built its reputation on paraphrasing specifically, and it still shows: 9+ named modes, from Academic to Creative to a Custom mode you configure yourself, cover a range of rewriting needs that a general AI writer tends to handle less precisely. Free caps at 125 words; Premium removes the limit and unlocks every mode along with the ability to save custom presets.
The rest of the suite, a grammar checker, plagiarism checker across 100+ languages, AI Detector, and AI Humanizer, comes bundled at roughly $9.95/month billed annually, alongside an AI Chat and Image Generator that round out the offering without being the reason most people subscribe. The Chrome extension, rated 4.7 across 6 million users, works across almost any web text field, not just a dedicated writing app.
QuillBot's academic backing through Learneo, the parent company behind Course Hero and Scribbr, shows up in its citation generator and academic-integrity framing for the plagiarism and detection tools. What it does not offer is a public API or the kind of deep multilingual reach Smodin markets, since its grammar checker specifically covers just 6 languages.
| Feature | Free $0/mo | Premium ~$9.95/mo (billed annually) | Team Plan Contact for pricing |
|---|---|---|---|
| Paraphrasing | Up to 125 words | Unlimited | Unlimited |
| Paraphrase modes | Standard & Fluency | 9 modes + Custom | 9 modes + Custom |
| Plagiarism checker | ✗ | 25,000 words/month | 25,000 words/month |
| AI Detector | Limited access | Unlimited | Unlimited |
| AI Humanizer | 125 words, 6 uses/day | Unlimited + insights | Unlimited + insights |
Smodin
AI writer, humanizer, plagiarism checker, and AI detector in one platform trusted by over a million users
Smodin's stack covers the same ground as QuillBot's, an AI writer, a humanizer, a plagiarism checker, and a detector, but leads with detection and humanizing as the primary workflow rather than paraphrasing. The detector claims 99.8% accuracy with results in under 2 seconds and sentence-level highlighting showing which passages are flagging, which is a specific and heavily marketed capability.
The multilingual reach is the clearest point of differentiation: 100+ languages across the writer, detector, and humanizer, aimed squarely at non-native English speakers and international students who need both language support and detection accuracy in the same tool. Starter runs around $9/month billed annually, undercutting QuillBot's Premium slightly, while Smodin Premium at $14/month adds unlimited output, bulk processing, and a Chrome extension.
Where it trails QuillBot is scale and specificity: one million-plus users against QuillBot's 35 million, and no equivalent to QuillBot's named, saveable paraphrase modes. Smodin's AI writer handles essays, homework summaries, and chat-style drafting well, but it is framed more generally than QuillBot's purpose-built rewriting engine.
| Feature | Free $0/month | Starter from $9/month (billed annually) | Premium from $14/month (billed annually) |
|---|---|---|---|
| AI writer | Limited | Standard | Advanced + Unlimited |
| AI content detector | Limited | Standard | Advanced |
| AI humanizer | Limited | Standard | Advanced (Turnitin-level) |
| Plagiarism checker | Limited | Standard | Advanced (academic sources) |
| Chrome extension | ✗ | ✗ | ✓ |
Head-to-head feature comparison
| Feature | ||
|---|---|---|
| User base | 35 million+ users | One million+ users |
| Paraphrase modes | 9+ named modes plus Custom, the flagship feature | No named multi-mode paraphraser |
| AI writer / drafting | Yes, via AI Chat, secondary to refinement tools | Yes, essays, summaries, rewrites, and chat |
| AI content detector | Yes, unlimited on Premium | Yes, 99.8% claimed accuracy, under 2-second scans |
| AI humanizer | Yes, unlimited plus insights on Premium | Yes, up to Turnitin-level bypass on Premium |
| Plagiarism checker | Yes, 25,000 words/month on Premium, 100+ languages | Yes, web and academic sources on Premium |
| Multilingual support | Grammar in 6 languages; plagiarism checker in 100+ | 100+ languages across writer, detector, and humanizer |
| Chrome extension | Yes, on every tier including free, 4.7 rating across 6M users | Yes, Premium only |
| API access | No public developer API | Limited on Starter, extended on Premium |
| Free tier | Yes, 125-word paraphrasing and basic grammar checking | Yes, but limited output and features |
| Starting paid price | ~$9.95/month (Premium, billed annually) | from $9/month (billed annually) |
Which should you choose?
Unlike most pairings in this category, this one is genuinely close because the two products overlap so heavily on feature set. QuillBot wins on scale, paraphrase-mode depth, and a Chrome extension available from the free tier, all of which matter if rewriting sentence-level phrasing is your main task. Smodin wins on multilingual breadth and a more explicit, heavily marketed detection accuracy claim, which matters more if your main task is verifying AI-assisted work will survive institutional or client scrutiny. Price is close enough at roughly $9 to $14 a month for either tool that it should not be the deciding factor.
Bottom line
Choose QuillBot if you want the more established, broader-featured suite with the deepest paraphrasing engine and a Chrome extension usable before you ever pay. Choose Smodin if your priority is multilingual reach or a stronger explicit claim around AI-detection accuracy, particularly for academic or Turnitin-adjacent use cases. For an English-first writer who paraphrases often, QuillBot is the better default; for a non-native English writer or a student facing strict detection policies, Smodin's multilingual and detection-first design is the better fit.
Frequently asked questions
What is the main difference between QuillBot and Smodin?
QuillBot leads with a paraphrasing engine offering 9+ distinct modes and a much larger user base of 35 million, while Smodin leads with multilingual reach across 100+ languages and a more heavily marketed AI-detection accuracy claim of 99.8%. Both bundle a similar stack of writing, detection, humanizing, and plagiarism-checking tools, but each treats a different piece of that stack as its core strength.
Which tool is better for non-native English speakers?
Smodin is the stronger fit for non-native English speakers, since its writer, detector, and humanizer all support over 100 languages as a core feature. QuillBot's grammar checker only supports 6 languages, though its plagiarism checker does cover 100+, so the multilingual gap is specific to grammar correction rather than the whole suite.
Is QuillBot or Smodin cheaper?
They are close. Smodin Starter runs from roughly $9/month billed annually, slightly undercutting QuillBot Premium at around $9.95/month, also billed annually. Smodin Premium at $14/month adds unlimited output and a Chrome extension, putting it slightly above QuillBot at the top tier. The price difference is small enough that feature fit matters more than cost.
Does Smodin have as many paraphrasing modes as QuillBot?
No, this is one of the clearest differences between the two. QuillBot offers 9+ named paraphrase modes plus a Custom mode you can save and reuse on Premium. Smodin's AI writer handles rewrites and drafting more generally through its writer and chat assistant, without a comparable named multi-mode paraphrasing tool.
Which tool has a more accurate AI detector?
Smodin publishes a specific claim of 99.8% accuracy with scans returning in under 2 seconds. QuillBot includes an AI Detector on Premium with unlimited checks but does not publish a comparable accuracy percentage, so a direct numeric comparison is not possible from either company's own published data.
Can I use the Chrome extension on the free plan for either tool?
QuillBot's Chrome extension is available on every tier including the free plan, giving immediate access to paraphrasing and grammar checking in the browser. Smodin's Chrome extension is Premium-only, so free and Starter users on Smodin need to use the web platform directly rather than an in-browser extension.

