6 Writing APIs To Elevate Your Words

Good writing makes the world go ’round. Whether it’s geared towards search engines, used within business-to-business copy, or taglines or social media videos, writing is what lets the world know of your existence, as well as what separates you from the seemingly endless sea of competition. In fact, Forbes even calls writing the most important skill in business.

Unfortunately, not everyone is a grammar expert. Luckily, there are many tools available to program copyediting abilities into any environment. In this post, we’ll cover six APIs to help improve writing. These APIs check for things like spelling, grammar, style, punctuation, plagiarism, readability, and diction to improve clarity.

Whether you’re developing an app with a smart text editor, or simply want to hone your own writing chops, these writing APIs can help elevate your writing and your business, letting you get creative and technical at the same time.

6 Writing APIs To Elevate Your Writing


If you’re looking for a writing tool that does it all, the ProWritingAid API could be the ticket. ProWritingAid (PWA) is predominantly known for two main services: Editing and Plagiarism Checker. It’s a one-stop-shop for everything that nearly anybody who uses writing in any capacity.

The ProWritingAid API lets developers integrate all of the software’s functionality into your projects. PWA lets you optimize your writing for seven different styles, ranging from Business to Web. It also checks the text for other grammatical issues. It checks for passive voice, for instance, which is a pervasive issue. It also looks for over-used words, spelling errors, and inconsistencies. It offers synonym suggestions, as well, to help keep your writing more interesting and engaging.

ProWritingAid is largely intended for creative writers, especially fiction writers. The ProWritingAid API has been used for a wide variety of projects, though. It’s been used to check medical transcriptions for errors and integrated into a HelpDesk chat function to help ESL tech support workers avoid grammatical errors.

ProWritingAid features unlimited grammatical checks, which sets it apart from other writing APIs. ProWritingAid is available as a free edition, allowing up to 500 calls for no charge. Beyond that, it’s $100 for 10,000 calls. There are plans available for larger volumes, as well.

The ProWritingAid API is easy to integrate into your development projects. There are pre-build SDKs for a number of popular languages. These include C#JavaScriptPHPPython, and Java.


If you’re looking for a slightly more stripped-down but still effective API for checking spelling and grammar, GrammarBot is a good pick. GrammarBot was created to fill a need for affordable grammar detection software. A team of natural language processing, machine learning, and AI experts went one step further still and made the API completely free for anyone to use.  GrammarBot is also quite easy to use. All you need to do is get an API key, then make a simple API call. Your answers are returned in a simple JSON format. The GrammarBot developers have even compiled quickstart guides for most major programming languages: PythonRubyJavaPHPNodeRustC#/.NET, and Perl.


Did you know that the average reading level in the United States is seventh to eighth grade? Readable is an API that scans text to determine readability. It factors in sentence structure, complexity, and word usage, among other factors.

Readable’s readability score is based around the Flesch-Kincaid scale, which is the most commonly used test for determining the reading level. It also incorporates the Gunning Fox Index, SMOG index, and other methods of determining a text’s difficulty.

Readable analyzes text for other common grammatical considerations, such as word density, average word length, and sentence complexity. It also performs higher-level analyses like sentiment analysis, speaking, and reading times.

Targeted toward copywriters, marketers, and eCommerce entrepreneurs, Readable shows the user where specific changes need to be made, using an overlapping system of algorithms. It takes the guesswork out of how to improve your writing.

The Readable Scoring API can easily be integrated with a wide number of third-party applications. It works seamlessly with Slack, for instance, ensuring that your chat dialogues and business communications are as professional as they need to be. Readable’s also able to assess text from any additional source, whether via uploading or by calling the API, meaning you can use it from any application.

Major companies like Salesforce and Shopify are already using readable, giving you an idea of how robust and well-developed this platform is.

Readable is available as a free trial. Beyond that, there are a variety of price points, ranging from $5 – $77 a month.

Readable’s Slack integration.


Writing APIs can improve your writing in so many different ways. The Wordsmith API takes that one step further, actually doing the writing for you.

Wordsmith is an API generated by Automated Insights that transforms data into writing using the latest natural language processing (NLP) tools. It can be used to power everything from AI chatbots to eCommerce materials, all of which can be updated in real-time via the API.

Wordsmith is customizable in a wide variety of ways, letting you fine-tune the language for your particular needs. It also offers real-time analytics so you can see how your material is performing.


Did you know that the average American has a vocabulary of about 20,000 words? What if you’re tired of using the same old words over and over again, though? Datamuse might be able to help.

Datamuse is a word recommendation API. It’s much more than a thesaurus or rhyming dictionary, however. The Datamuse API is widely customizable, letting you fine-tune the search results by meaning, sound, and context.

The Datamuse API is used to integrate a word-finding query engine. Datamuse has been used to power everything from RhymeZone, the Internet’s leading rhyming dictionary, to VoiceDream Writer, a writing assistance app. It’s also used by SmashWords for their search autocomplete function.


The Internet can be an excellent tool for writers. However, the research process can quickly become unorganized. Organizing hundreds of tabs and bookmarks, for example, is an arduous process.

Classeur is an API that allows developers to integrate notes, documents, and blogs into their workflow using Markdown language. Users can create an infinite number of files, folders, and directories, known as classeurs. Users can export this information as a PDF, EPUB, or .doc. for collaborative purposes.

Final Thoughts

The world becomes increasingly text-driven as the Internet intertwines with our daily lives. Having tools to enhance your copy gives you a leg up against anyone who doesn’t realize the importance of good writing, which is all too prevalent in today’s world. Embedding a writing API into your workflow could bring a competitive advantage and streamline content creation processes.

Are you using a different writing API within your app? Please let us know in the comments below!