Choosing AI for proofreading depends on how you revise: correcting small errors while typing, comparing alternative sentences, or checking work in several languages. Start with the kind of change you want, then test whether the tool preserves your meaning.
This guide compares Grammarly, DeepL Write, and LanguageTool for that editing stage. Our blogging and marketing tool guide covers the wider content workflow, while this article focuses on a draft you already have. Product details were checked against official guidance on September 10, 2026. The recommendations are editorial judgments, not an accuracy ranking from a product benchmark.
In This Guide
- Choose by editing task
- Grammarly for everyday writing
- DeepL Write for alternative wording
- LanguageTool for supported languages
- Review a corrected paragraph
- Check feature access
- Keep control of the final version
Choose AI for Proofreading by the Revision You Need
| Your situation | Consider first | What to verify |
|---|---|---|
| You want suggestions while writing everyday documents | Grammarly | Support in your writing app, language, and plan |
| You want to compare ways of expressing an existing idea | DeepL Write | Alternative wording, preserved meaning, and platform limits |
| You regularly check drafts in several supported languages | LanguageTool | The depth of checking for each language and website versus extension access |
| You need to verify claims, sources, or the argument itself | A separate editorial review | Evidence and reasoning beyond surface corrections |
A tool can fit more than one row. Treat the table as a shortlist for a trial using your own kind of writing. The best fit is the one whose useful corrections outweigh the time you spend rejecting or repairing suggestions.
Grammarly: for People Who Want Feedback While Writing
Consider Grammarly when you write frequently and want feedback in the apps where you work. Its feature overview describes suggestions covering grammar, spelling, punctuation, wording, and tone, with desktop support across various apps and websites.
This may suit an office worker polishing reports or a writer who wants to review small corrections as they appear. In a trial, distinguish an actual error from a style preference. A suggestion to shorten a sentence may help, while replacing a familiar technical term could make the document less useful to its intended audience.
Grammarly is no longer accurately described as English-only. Its multilingual guidance lists Korean and other languages, with differences in correction types, platforms, and access. Test the exact language and app combination; do not assume every advanced English feature works identically elsewhere.
The plan comparison separates Free features from Pro options such as full-sentence rewrites and tone adjustment. Seeing a tone assessment and receiving a rewrite that changes the tone are different capabilities. Decide which one you need before choosing a plan.
DeepL Write: for People Comparing Sentence Alternatives
Consider DeepL Write when you have an idea in place but want clearer phrasing. Its product guide describes corrections and alternative wording, and lists supported languages including English and Korean. Write support has its own scope; do not infer it from the languages available in DeepL Translator.
The customization guide explains selecting alternatives for words or phrases and using style or tone controls. It also says alternative phrasing is unavailable in the mobile apps. Check the feature on the platform you intend to use.
This may suit someone revising a short introduction, explanation, or translated draft. Compare each alternative against the original idea. If a rewrite makes a tentative statement sound certain, keep the uncertainty or reject that suggestion. Natural phrasing is useful only when it expresses what you meant.
A practical approach is to revise one paragraph at a time, then read the whole document for consistency. A sentence can improve in isolation while repeating a point made in the previous paragraph. The final decision still depends on the surrounding text.
LanguageTool: for Writers Who Need Language-Specific Checking
Consider LanguageTool when you work in several languages and want to inspect its coverage for each. Its language guide lists supported languages and variants. It also explains that checking depth differs: for example, some listed languages do not have spell checking. Korean is not on that list.
Premium adds more checks for a specified set of languages, including English, German, French, Spanish, Dutch, Polish, and Portuguese. The Premium page also describes AI sentence paraphrasing and style-guide features. A long supported-language list should not be read as an identical feature set for every language.
This may suit a multilingual writer who can evaluate suggestions in each target language. Try a paragraph with an intentional typo, an agreement error, and a legitimate specialist term. Check whether the tool finds the errors while allowing you to retain the correct term.
Account for an important access change: LanguageTool’s extension announcement says its hosted browser extension requires Premium after the trial. The website remains available for free. A recommendation based on the old free-extension model can therefore lead to the wrong choice for someone who needs ongoing suggestions inside websites.
Worked Example: Fix Grammar Without Inventing Evidence
The following paragraph and revisions are original editorial examples, not outputs attributed to any of these services.
The pilot results shows that 11 of 20 invited staff used the checklist. This suggest the checklist may be useful, but we did not measure time saved.
A minimal correction is:
The pilot results show that 11 of 20 invited staff used the checklist. This suggests the checklist may be useful, but we did not measure time saved.
Two agreement errors changed: “results shows” became “results show,” and “This suggest” became “This suggests.” The numbers, uncertainty, and missing time measurement remain intact. The paragraph is grammatically improved, but its cautious interpretation still deserves editorial review: usage alone does not demonstrate usefulness.
A more evidence-focused version is:
In the pilot, 11 of 20 invited staff used the checklist. We did not measure time saved, so these results establish uptake but do not show an efficiency benefit.
This second revision changes the interpretation as well as the grammar. Label that as an editorial decision. It makes the limitation explicit instead of allowing participation to stand in for evidence of an efficiency improvement.
Reject a rewrite such as “The checklist improved efficiency for 55% of staff.” Eleven divided by twenty is 55%, but the measured event was checklist use. A correct percentage does not justify attaching it to an unmeasured outcome.
When testing a writing assistant, keep these acceptance criteria next to the source:
- The two agreement errors should be corrected.
- The counts must remain 11 and 20, with invited staff as the denominator.
- Usage must not become satisfaction, time savings, or proven effectiveness.
- The absence of a time measurement must remain visible.
- A substantive change in interpretation should be reviewed separately from punctuation or grammar.
Check the Actual Feature Before Paying
For Grammarly, test the suggestions available in your account rather than relying on a general claim about AI writing. The linked plan page distinguishes basic assistance, rewriting, and generation. A trial can help establish whether an advanced feature solves a recurring editing problem.
For DeepL, a Translator Pro subscription does not automatically include Write Pro. The Write account guidance distinguishes text limits and subscription types. Check the product included in your plan before moving a long document into the workflow.
For LanguageTool, decide whether copying a passage into the free website is enough or whether you need its paid browser extension. Test the language-specific corrections you care about. Do not pay solely for a high total number of checks across languages you never use.
For workplace drafts, use an approved account and the organization’s sharing rules. Use invented or non-sensitive text for an initial comparison. Evaluate the finished revision and review effort, not just how many underlines a service displays.
Separate Correction, Style, and Editorial Judgment
Review changes in three passes. First, fix spelling, grammar, and punctuation. Second, consider clarity and tone for the intended reader. Third, check whether any rewrite changes a fact, a condition, the strength of a claim, or the writer’s voice.
Keep the original draft so you can compare versions. Accept suggestions deliberately, especially around quotations, product names, numbers, and technical terms. Fewer flagged issues do not prove that a document is accurate or well argued.
For message-specific examples, use our AI email revision guide. If the source and target languages differ, consult the translation tool comparison. Check factual claims with the AI fact-checking workflow, and find more options in the AI guides hub.