Diglot vs Grammarly
The dominant brand in broad AI-assisted writing — strongest for users who already think in English.
Where Grammarly ends and Diglot begins
Grammarly is the strongest brand in broad AI-assisted writing. If you write in English natively and want to polish what you produced, it's a category-defining tool. Diglot is built for a different writer: someone who thinks in one language and publishes in English. The comparison below is honest — Grammarly wins for several use cases, and we say so.
What Grammarly sells, where Diglot is different
What Grammarly sells
- Confidence at scale across every app
- Cross-platform writing assistance (browser, desktop, mobile)
- Enterprise-ready governance — style guides, snippets, analytics
- Multilingual support layered on an English-first base
- Team controls and brand tones
Why Grammarly wins
- Strongest trust and brand recognition in the category
- Broadest perceived coverage for mainstream English users
- Huge integration footprint (Word, Google Docs, Outlook, all browsers)
- Strong team and admin packaging
- Increasingly credible multilingual story
Where Diglot is positioned differently
Grammarly is broad, not sharp. It is built for users who already think in English and want to improve what they wrote. Diglot is built for users who think in another language first, draft bilingually, and need translation + rewrite + grammar in one workflow rather than three tabs. We don't claim a better grammar checker — we claim a better fit for non-native English writers.
Feature-by-feature comparison
| Feature | Grammarly | Diglot |
|---|---|---|
| L1-aware grammar correction (treats errors as transfer patterns, not random typos) | No — corrects errors locally without L1 context | Yes — flags Russian/Spanish/Chinese/Japanese/Korean/Arabic transfer patterns explicitly |
| See data/pseo-moat/l1-errors/ for our 84-pattern KB across 6 L1s. | ||
| Bilingual drafting (write in L1, output English in same session) | Partial — translation is a separate flow | Native — L1 → English is the primary workflow |
| Cross-app browser/desktop extension | Mature, present everywhere | Browser extension shipping Stage 5.1 |
| Plagiarism check | Premium tier | Included on Spark tier |
| Authorship Certificate (cryptographic proof you wrote it, not AI) | ✗ | Included on all plans |
| Useful when AI detectors falsely flag non-native English at ~2× the rate of native (Stanford 2023). | ||
| Team and enterprise controls | Mature — style guides, snippets, brand tones, analytics | Roadmap — Stage 7+ |
| Free tier usable for real work | Limited — most useful features behind Premium | Yes — meaningful daily word allowance |
Deep dive: why L1-aware grammar correction changes the work
The core architectural difference between Diglot and Grammarly is what the grammar engine *knows about you*. Grammarly's engine is language-agnostic — it sees your sentence «We measured temperature of sample» and flags it as «missing article: the». You add «the», submit your essay, and three months later you're still dropping articles in front of specific nouns because nobody told you WHY. The error is fixed locally; the underlying pattern stays.
Diglot's engine, when configured for Russian (or one of the other 5 deeply-modeled L1s), recognizes the same sentence as the `article-omission-specific` pattern — a known Russian-to-English transfer where Russian's lack of an article system causes specific-reference articles to drop on every cycle. The correction surfaces with context: «Russian writers face this on first-mention specific nouns; Wade 2010 documents the pattern across academic Russian-English writing. Here's the example→corrected pair you can recognize next time.» You're not just fixing this sentence — you're calibrating your future writing.
This matters more than it sounds. ESL writers report «I correct my English and it still sounds translated» as their top frustration. The reason: surface error correction without L1 explanation gives the writer no model for the underlying drift. After a year of Grammarly use, a Russian researcher's English often still reads as Russian-influenced because the corrections didn't build a model of the transfer signature. After three months of Diglot use, the same writer typically internalizes the top 4-5 transfer patterns and the «sounds translated» frequency drops noticeably — because each correction is also a small lesson.
Grammarly's bet is breadth (every app, every writer, generic corrections). Diglot's bet is depth (one editor, the specific ESL writer, L1-modeled corrections). Both bets are real and serve different audiences. If you write in English natively and want surface polish across all apps, Grammarly's breadth wins. If your hardest problem is escaping your L1's transfer signature, Diglot's depth is the tool built for that.
Same task, both tools: writing a research abstract
You're a Russian PhD student writing the abstract for a materials science paper. Your draft (in your head): «We measured temperature of sample during heating to 800°C. The result significant. Method robust to noise. Three of paper presented at conference last year.» Here's what each tool does.
With Grammarly
- Paste into Grammarly: 4 errors flagged.
- «temperature of sample» → suggested «the temperature of the sample» (no explanation why).
- «result significant» → suggested «result is significant» (flagged as «missing verb»).
- «Method robust» → suggested «Method is robust» (same generic flag).
- «Three of paper» → flagged as «possible typo», suggested «Three of papers» (wrong — should be «Three papers»).
The downside: Three of four corrections are surface-only. Grammarly didn't explain the underlying Russian transfer pattern (article-omission, copula-deletion, classifier-influenced phrasing). You fix this abstract, but the next abstract will leak the same patterns because the engine taught you nothing about why.
With Diglot
- Paste into Diglot (configured with Russian as L1).
- «temperature of sample» → `article-omission-specific` (Wade 2010): Russian has no article system; specific-reference articles drop. Example→corrected pair shown.
- «result significant» / «Method robust» → `missing-copula-be-present`: Russian present tense omits копулу («дом большой» = house big). Both flagged with same pattern key.
- «Three of paper» → `classifier-of-leak`: pattern shared with Mandarin speakers, sometimes appears in Russian writers exposed to Mandarin. Suggested «Three papers».
- After correction, Authorship Certificate logs your keystrokes as proof of human authorship — useful if the abstract later gets falsely flagged by Turnitin / GPTZero.
The upside: Each correction is also a small lesson. After 2-3 weeks of consistent Diglot use, a Russian researcher reports recognizing article-omission as it happens, before the engine flags it. The engine gradually fades into the background as the writer internalizes the L1-transfer signature.
When Grammarly is the right pick, when Diglot is
Grammarly wins when
- You write in English natively and want correction across every app
- Your team needs enterprise admin controls and brand-tone enforcement today
- You want the biggest-brand default and your buyer values trust over fit
- You only need polish on already-English drafts, not bilingual workflow
Diglot wins when
- You think in another language and your English drafts get flagged as "translated-sounding"
- You repeatedly copy-paste between Translate, ChatGPT, and Grammarly all day
- You need translation + rewrite + grammar in one editor, not three tabs
- Your essay was falsely flagged as AI by Turnitin/GPTZero and you need authorship proof
Switching from Grammarly to Diglot — practical guide
If you've decided to switch (or pilot Diglot alongside Grammarly), here's the practical migration path. Honest about friction: Grammarly's cross-app footprint is the thing you'll miss most until Stage 5.1 ships the Diglot browser extension. Plan accordingly.
1. Identify your primary writing surface
Where do you actually do most of your writing? Google Docs, Word, Notion, native web editor? If it's a single document tool, Diglot's web editor (web.diglot.ai) replaces it cleanly. If you write across many apps, keep Grammarly for the spillover apps initially and use Diglot for primary document work.
2. Sign up for the free tier first
No credit card needed. Free tier is meaningful for daily writing — typical ESL undergrad workload fits without hitting limits. Spend 1-2 weeks writing as you normally would; pay attention to L1-aware grammar feedback as a learning signal, not just corrections.
3. Run your existing English drafts through Diglot
Take a paragraph from a recent essay or business email. Paste it into Diglot and run grammar check. Compare what Diglot flags vs what Grammarly flagged. The Diglot output should include both surface errors AND the L1-transfer-pattern naming for each. This is the «aha» moment most ESL writers report.
4. Decide on Spark vs Pro for longer work
Spark ($19/mo) adds larger AI quotas + plagiarism check + Authorship Certificate without limits — sufficient for most undergrad/grad work. Pro ($29/mo) adds premium AI models (better academic register) — worth it if you write research papers, theses, or professional documents regularly.
5. Cancel Grammarly when comfortable
If you're keeping Grammarly's browser extension for cross-app coverage, downgrade to Grammarly Free (still useful) and run Diglot Spark/Pro for primary work. If you're going all-in on Diglot, cancel Grammarly entirely once the Stage 5.1 browser extension ships (estimated Q3-Q4 2026).
Honest about friction: Real friction points: (1) Grammarly's Microsoft Word desktop integration is mature; Diglot doesn't have an equivalent yet. (2) If your team uses Grammarly Business with shared style guides, those don't migrate. (3) Diglot's free tier is more generous than Grammarly Free for daily writing, so the «free tier reset» is rarely a problem.
Pricing
Grammarly
Grammarly Free, Pro ~$12/mo individual, Business ~$15/seat/mo (billed annually, publicly listed)
Diglot
Free tier + Spark ($19/mo or $190/yr) + Pro ($29/mo or $290/yr). Free tier is usable, not crippled.
Pricing verified 2026-04-13. Public pricing changes — confirm on each vendor's site before purchase.
Sound like you? Try Diglot free.
If «you think in another language and your english drafts get flagged as "translated-sounding"» describes your work, the free tier is meaningful for daily writing — no credit card.
Start for freeFrequently asked questions
- Is Diglot a Grammarly alternative for ESL writers?
- Yes — that's the specific audience Diglot is built for. Grammarly works well for users who already write in English natively. If your first language is something else and your English writing gets flagged as sounding translated, Diglot is the tool you should evaluate. We don't replace Grammarly for native English users.
- Can I use Diglot in Google Docs and Word like Grammarly?
- Not yet across all surfaces — Diglot's editor is currently web-first (web.diglot.ai), with a browser extension in Stage 5.1 and Google Workspace Add-on shipping in Stage 5.2. Grammarly's cross-app footprint is larger today. If cross-app extension is your primary need, Grammarly wins; if bilingual workflow is, Diglot wins.
- Does Diglot do everything Grammarly does?
- No — and we don't try to. Diglot includes the core writing tools (grammar, rewriting, translation, plagiarism check, AI detection defense), but we don't replicate Grammarly's enterprise admin layer or its integration footprint. We focus on what non-native English writers actually need.
- Is Diglot more expensive than Grammarly?
- Diglot Spark is $19/mo (or $15.83/mo annual), Pro is $29/mo (or $24/mo annual). Grammarly Pro is around $12/mo. We are positioned above on price because we include workflow tools (translation, Authorship Certificate, L1-aware corrections) that Grammarly does not, and our free tier is more useful for real daily work.
- Can I use Grammarly and Diglot at the same time?
- Technically yes — they don't conflict architecturally. In practice, running both editors over the same text creates noise: Grammarly flags generic surface errors while Diglot flags the same errors as L1-transfer patterns. Most users who tried both keep Grammarly for cross-app coverage (Slack, Outlook drafts, anywhere outside the writing tool) and use Diglot exclusively for longer document work. Once Diglot's browser extension ships (Stage 5.1), the cross-app gap narrows and the dual-tool pattern becomes unnecessary for ESL writers.
- What about Grammarly's Premium AI generation features?
- Grammarly Premium added GPT-style generation in 2023 — write a prompt, get drafted text. Diglot's Cowriter (SPEC-49) is the parallel feature, with three modes: Ask (answer questions about your draft), Edit (transform selected text), Plan (outline a structure before writing). The architectural difference is that Cowriter preserves YOUR voice — it suggests, you accept/edit, and Authorship Certificate logs your keystrokes as proof. Grammarly's generation feature inserts AI text at scale without that authorship-preservation chain.
- Will switching from Grammarly cost me my saved settings or style guides?
- If you've invested heavily in Grammarly's enterprise style guides, snippets, or brand voice tuning, those don't migrate — they're proprietary to Grammarly's admin layer. For individual users with no enterprise config, there's nothing to migrate; just sign up and start. Diglot's equivalent (team admin, custom glossaries) is shipping in Stage 7+. For now, individual ESL writers gain L1-aware corrections + Authorship Certificate; enterprise teams should pilot Diglot alongside Grammarly rather than swap.
