Diglot vs Grammarly for ESL Writers: Which Tool Fits Better?

Grammarly is the most widely used writing assistant in the world. Tens of millions of people use it daily. But there's a specific group of writers for whom Grammarly was never really designed: people for whom English is a second language.

If you're a non-native English speaker — a student writing academic papers, a professional sending business emails, or a bilingual creator publishing content — the question isn't just "does this tool fix my grammar?" It's "does this tool understand why I'm making these mistakes, and does it help me work the way I actually work?"

This comparison breaks down Grammarly and Diglot across the dimensions that matter most to ESL writers.

Who Each Tool Was Built For

This is the most important distinction, and it shapes everything else.

Grammarly was built for native English speakers who want to write better. Its suggestions are calibrated around the assumption that you already think in English — you just need help with clarity, tone, and correctness. It's excellent at what it does for that audience.

Diglot was built specifically for non-native English speakers: people who think in one language and need to produce professional English. The entire product — the bilingual editor, the translation integration, the AI Cowriter, the paraphrasing tool — is designed around the workflow of someone whose native language is not English.

This difference in design philosophy shows up in every feature comparison below.

Grammar and Spelling Correction

Both tools correct grammar and spelling. On this dimension, Grammarly has an edge in sheer coverage — it has been trained on enormous amounts of native English text and catches a wide range of errors including style issues, passive voice, and tonal problems.

However, for non-native speakers, the most painful grammar errors are not the ones Grammarly prioritizes. Article usage (a, an, the), preposition errors ("interested in" vs "interested about"), and verb tense confusion are the hardest problems for ESL writers — and they're also the hardest for any AI to fix reliably, because they depend on context and meaning rather than pattern matching.

Diglot's grammar checker is built with non-native patterns in mind. Combined with the AI Cowriter, it not only flags errors but helps you rephrase the sentence in a way that sounds natural — not just grammatically correct.

Verdict

Grammarly has broader grammar coverage overall. Diglot is more useful for the specific types of errors non-native speakers make most often.

Translation and Bilingual Workflow

Grammarly has no translation feature. It operates entirely in English. If your workflow involves drafting ideas in your native language and working them into English — which is how most non-native writers actually work — Grammarly offers no support for that process at all.

Diglot is built around the bilingual workflow. The editor lets you keep native-language notes alongside your English draft. The built-in translator supports 71 languages and works directly within the writing interface, so you're never copying text between tabs or switching apps to translate a phrase.

For someone whose writing process looks like: "draft in Russian / Chinese / Spanish → refine in English," Grammarly is useful only in the second half of the process. Diglot supports the entire workflow.

Verdict

Diglot wins clearly. Grammarly has no bilingual functionality. This is the single biggest differentiator for non-native writers.

Paraphrasing and Rewriting

Grammarly's rewriting suggestions operate at the sentence level — it will flag a clunky sentence and offer a cleaner version. But it doesn't have a dedicated paraphrasing mode where you can actively rework a paragraph with different tone or style options.

Diglot has a standalone paraphrasing tool with multiple modes. For non-native writers, this is not just a convenience — it's a learning mechanism. When you see how the same idea can be expressed three different ways in natural English, you build vocabulary and phrasing intuition faster than any grammar drill.

This matters especially for writers who know what they want to say but aren't sure how to say it in idiomatic English. Grammarly corrects what you wrote. Diglot helps you find a better way to say it.

Verdict

Diglot is stronger for non-native writers who need active rewriting support, not just error correction.

AI Writing Assistance

Grammarly has added AI writing features (GrammarlyGO) that can generate text, rephrase content, and adjust tone. It works reasonably well for native speakers who need a polish pass or a quick draft.

Diglot's AI Cowriter is specifically designed for non-native speakers who need more than polish — they need help structuring ideas in English from the ground up. The Cowriter can extend a draft, restructure a paragraph, or help find the right English phrasing for an idea that came to you in another language.

The key distinction: Grammarly's AI is designed to enhance English. Diglot's AI is designed to bridge the gap between your native language and professional English output.

Verdict

For non-native speakers specifically, Diglot's Cowriter is more aligned with actual needs. GrammarlyGO is strong but built for a different user.

Plagiarism Checker

Plagiarism checking matters most to ESL students writing academic papers — a core Diglot audience. Both tools offer plagiarism detection.

Grammarly's plagiarism checker is available only on paid plans and compares text against a broad database of web content and academic sources. It's well-regarded.

Diglot includes a plagiarism checker as part of its all-in-one workspace. For students who are already using Diglot for grammar correction, paraphrasing, and translation, having plagiarism checking in the same interface removes one more reason to switch between tools.

Verdict

Both tools are adequate. Diglot's advantage is integration — everything in one place.

Platform and Integrations

Grammarly is deeply integrated into the broader ecosystem: browser extension, Microsoft Word plugin, Google Docs, desktop app. If you write across many different surfaces, Grammarly follows you everywhere.

Diglot operates as a focused writing workspace. The strength of this approach is that your entire writing process — translating, drafting, checking grammar, paraphrasing, checking for plagiarism — happens in one controlled environment. The weakness is that it requires you to bring your work into Diglot rather than having Diglot come to you.

Which model you prefer depends on your workflow. Writers who do most of their serious writing in one place benefit from Diglot's integrated approach. Writers who need correction across many apps and contexts benefit from Grammarly's reach.

Verdict

Grammarly wins on integrations. Diglot wins on depth of support in a single writing session.

Pricing

Grammarly's free plan covers basic grammar and spelling. Grammarly Premium — which includes plagiarism checking, advanced suggestions, and GrammarlyGO — starts at around $12/month billed annually.

Diglot offers a free plan with core features and paid plans that include the full AI Cowriter, unlimited paraphrasing, translation, and plagiarism checking. Pricing is competitive with Grammarly Premium, with the added value that you're getting translation and bilingual workflow tools that Grammarly simply does not offer at any price.

Verdict

At comparable price points, Diglot provides significantly more value for non-native English speakers because it covers the full writing workflow, not just the correction layer.

Side-by-Side Summary

The Bottom Line: Which Should You Use?

Choose Grammarly if: English is your native language, or you're already fluent and you need lightweight grammar correction that works across every app you use. It's the best tool in the world for that use case.

Choose Diglot if: English is your second language and your writing process involves translating, bridging two languages, or going from rough native-language ideas to polished English output. Grammarly will correct your English. Diglot will help you produce it.

The distinction matters most for:

• International students writing academic work in English
• Professionals who work in English but think in another language
• Bilingual content creators publishing for English-speaking audiences
• Anyone who has ever written a draft in their native language and then tried to make it sound natural in English

If any of those descriptions fit you, you're in Diglot's core audience — not Grammarly's.

Try Diglot for free and see how a tool built for your specific workflow feels different from a tool that was adapted for it.