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Grammarly Editor is an automated proofreader that corrects contextual spelling mistakes, checks for more than 250 common grammar errors, enhances vocabulary usage, and suggests citations.

Free proofreading tool for LibreOffice, Apache OpenOffice, Mozilla Firefox and Google Chrome. Also available as a standalone application. Supports about 20 languages (on different levels) and allows customization.

Hemingway App makes your writing bold and clear.The Hemingway Editor for Mac and PC highlights common errors. Use it to catch wordy sentences, adverbs, passive voice, and dull, complicated words.

A tool to check creative and technical writing for potential improvements.

Slick Write is a powerful, free tool that makes it easy to check your writing for grammar and spelling errors, potential stylistic mistakes, and other features of interest. Whether you're a blogger, novelist, or student writing an essay for school, Slick Write can help take your writing to the next level.

Writefull is a light-weight app that provides feedback on your writing by checking your text against databases of correct language.

ProWritingAid is your free online writing editor and personal writing coach. Of course it checks your grammar but it does much more to help you improve your writing:

Grammar & Spelling Check; Free Online Proofreading; No Downloads...Allows you to find those pesky mistakes and correct them before your teacher does...

Online grammar check, proofreading and copy editing services. Our professional grammar editors will give you online proofreading and copy editing services at affordable prices.

VirtualWritingTutor is a 100% free grammar checker that finds common spelling and grammar errors in English for learners of English as a Second Language.

Analyze My Writing is an online text content and readability analyzer. Copy and paste a text into the homepage and gain a wealth of information about your text including word and character counts, word and sentence lengths, the readability of your text, and other analyses.

Document Grader highlights areas in your writing that need attention and provide you with either automatic fixes or helpful suggestions so you can fix the text yourself. The web based app provides detailed explanation and examples with every suggestion if an automatic fix wasn't found.

1Checker, the best free grammar checker, which grants you free instant text check for various mistakes and offers you enrichment suggestions to write better English.

Expresso is a little tool to edit texts and improve your writing style. It will teach you to express yourself through writing more efficiently and help make your texts more readable, precise, and engaging.