WebSpellChecker API

Enrich your application to feature grammar and spell check in many languages through API queries to the robust WebSpellChecker engines. Gain developer level access to build and extend proofreading functionality into your applications and website.

Try demos
Have spell- and grammar checking up and running in your app in under 30 minutes.

Easy integration

Have spell- and grammar checking up and running in your app in under 30 minutes.

Get truly global with 16 languages covered by default and 152 additionally available.

80+ languages

Go global with 80+ languages. Juggle 2+ languages easily when typing with the auto-detection feature.

The language changes every minute. We make sure to keep your spelling up-to-date with regular dictionary updates.

Evergreen dictionaries

Tired of Reddit being replaced with redish? Calm down, our evergreen dictionaries consist of buzzwords and modern terms to make you sound relevant.

We love when our clients enjoy our products. So we take every client’s need as our own.

Caring support

We love when our clients enjoy our products. So we take every client’s need as our own.


Languages support

Have your spelling professionally checked in many languages. Here are just some of them:

  • American English
  • British English
  • Canadian English
  • Canadian French
  • French
  • German
  • Italian
  • Greek
  • Spanish
  • Finnish
  • Danish
  • Dutch
  • Portuguese
  • Swedish
  • Norwegian Bokmal
  • Brazilian Portuguese
  • Ukrainian

If your app’s audience speaks languages different from the listed ones, check the full list of available languages here.

There’s an extra option – language auto-detection. Just switch it and your cocktail of 2+ languages will be meticulously checked. No hassle around manual settings configuration – your proofreading engine is automatically fine-tuned for each and every language.


  • - Spell checking
  • - Grammar checking

Grammar checker

It’s not only spelling that matters, but also how the words click with each other. The grammar checker can recognize and correct a variety of sentence-level mistakes.

  • Intelligent recognition of sentence-level mistakes in over 20 languages.

  • Smart context-based correction suggestions. The grammar checker offers the replacement options based on the general topic of the text.

User and company-wide custom dictionaries

Each company is a state of its own with its own language and rules. Tune your proofreading tool to make sure your employees, brands, and product names are always spelled right.

  • User-level dictionaries allow each of your app’s users to create their own vocabulary, which can be used across multiple sites that use one of the WebSpellChecker products.

  • Custom dictionaries are company-wide vocabularies, which are created and set at an admin level on top of the base languages. Vocabularies can be customized for particular user groups within your company.


API allows you to build the proofreading tool up to your app’s specific needs. A set of grammar and spell checking commands, and additional parameters provide you with access to all the power of the WebSpellChecker engine.

Frequently asked questions

The Server licensing is particularly suitable for companies with enhanced security requirements, since it allows all the proofreading requests to be processed within your own servers. The Cloud plans eliminate your infrastructure and maintenance costs for proofreading engine, ensuring quick start within your current setup.

If you still hesitate, feel free to get in touch with us. We will be happy to schedule a call with you to discuss the most suitable solution for you.

Yes, you can evaluate both Cloud and Server versions of the WebSpellChecker products for free. The evaluation period for the Cloud version is 14 days, for the Server version is 30 days.

  • WebSpellChecker Server. In order to get an evaluation copy of the application, request a 30-day trial version from our website.
  • WebSpellChecker Cloud Services. Unlike the Server version of the WebSpellChecker application which provides the full set of the products, with WebSpellChecker Cloud Services each product is provided as a separate subscription. Thus, before subscribing, you need to choose which product you plan to integrate and use.

There are three types of products available:

  • WebSpellChecker Proofreader (WProofreader)
  • SpellCheckAsYouType (SCAYT) Plugin for CKEditor 4
  • WebSpellChecker Dialog (WSC) Plugin for CKEditor 4
  • WebSpellChecker Web API (Web API)

As soon as you defined which type of the product you need, you can subscribe to 14-day trial version from our website accordingly.

If you end up exceeding the limit, the service will stop working. However, our team monitors the usage, and notify customers beforehand with the proposal to purchase another set of words. In this case, the price depends on the potential customer usage (per year) and the price of the appropriate usage plan.

Please see the complete Terms of Service for the Cloud services.

Please check the Software License Agreement which contains the complete terms and conditions for downloading, installing and using the Server version of the WebSpellChecker software.

There is a list of options available how you can order the WebSpellChecker products:

  • You may purchase the licenses or subscribe to the services directly from our official website. If you are ordering from website, you will be prompted to pay with a credit card or using PayPal account. As soon as the payment is received, you will receive an email confirmation with the license(s) or subscription information.
  • If you prefer submitting the payment via wire transfer and have a formal invoice, you need to contact our sales team by specifying the items that you would like to purchase.

The license and source downloads (if applicable) will only be made available online when full payment is confirmed.

According to Commercial License Fees and Warranties clauses of our standard Software License Agreement, you have an option to request a refund of your commercial server license up to 30 days after the original date of purchase. However, such a refund option is possible only in case WebSpellChecker software breaches the given warranty.

After the 30-day period after the original date of purchase, refunds will not be available.

To request a refund within 30 days of payment, please contact our sales team.

The refunds for WebSpellChecker Cloud Services are only available within the first paid month after the evaluation period for monthly subscriptions and within 30 days of payment for annual subscriptions. After these periods the refunds are not offered.

To cancel your evaluation/subscription for WebSpellChecker Cloud Services, please follow the instructions below:

  • Log in to your WebSpellChecker account.
  • Go to the Profile section and click the Cancel button to request the cancellation of your subscription.

The WebSpellChecker Cloud Services subscription will be terminated at the end of the current billing cycle and your credit card will not be charged again. No credit is offered for canceling an account prior to the end of a billing cycle.

Separately, the subscription is considered terminated upon non-payment at the end of the current billing cycle.

To request a refund during the first month of paid service (following an evaluation) or within 30 days of payment for an annual subscription, please contact our sales team.

All the international payments to WebSpellChecker LLC, are processed by our official reseller in Estonia, TeamDevManagement OU (VAT #EE101929530).

The next following payment methods are accepted:

  • Credit card. For credit card payments we use PayPal payment system. PayPal supports a large number of credit cards, including Visa, MasterCard, American Express, Discover, JCB, Diner’s Club and EnRoute. Depending on your processor, Payflow Pro also supports level 2 and level 3 Purchasing Cards (P-Cards). Check cards or debit cards with either a Visa or MasterCard logo are supported and treated just like a credit card.
  • PayPal
  • Bank transfer. The wire transfer payment can take up to 7-14 business days for bank transfers to clear through our banking facilities. You can email your remittance advice to info@webspellchecker.net.

WebSpellChecker’s payment terms for WebSpellChecker Cloud Services are strictly NET0, the payment terms for the WebSpellChecker Server, Maintenance Renewal or the additional software are NET30. In both cases, the license key(s) or subscription(s) details will only be made available after full payment is received. If you have placed your order but find that you are waiting for your organization to make the payment, you can contact us and request a fully-functional evaluation license key to help you cope with any bureaucratic delays.

The next payment methods are not supported and can’t be accepted:

  • Checks. Any check which will be mailed to WebSpellChecker LLC or TeamDev Management OU won’t be accepted. Our banks do not recognize checks validity, thus, we won’t be able to cash them.
  • ACH (Automated Clearing House) payment.

By default WebSpellChecker doesn’t offer any discounts for WebSpellChecker Server or WebSpellChecker Cloud Services. Our goal is to build reliable and quality products available at the best price and to treat every customer equally. The prices are available for everyone so there’s no guessing or uncertainty around what you’re buying and how much it costs.

We do provide various integrations where you can use the free version of the WebSpellChecker products which are provided as a part of WebSpellChecker Cloud Services:

  • WebSpellChecker (WSC) and SpellCheckAsYouType (SCAYT) plugins for CKEditor 4. Both plugins are shipped integrated by default with CKEditor 4.0+.
  • WProofreader plugin for WordPress
  • WebSpellChecker App for Slack

The free versions of the mentioned products have certain limitations and provided with banner ads. In order to lift the limitations and get rid of the banners, the migration to the paid version is required.

We do offer our customers Data Processing Addendum, it forms a part of Terms of Service. Here you can find all the materials related to our commitment and compliance with GDPR.

We have an extensive Privacy Policy in place to protect your and your end users’ texts. Please see the details here.

Web API specific questions

A single API request is limited to 50KB of text, which equals 50K characters including spaces. If you plan to have larger requests, please consider splitting such requests into smaller chunks.

If you are holder of the Server solution, you can increase this limit using AppServer settings.