Datamuse Autocomplete Service

What is it?

Autocomplete is the feature on many search boxes that guesses what you've started to type.

You've probably seen autocomplete at work on sites like Google and Amazon.com. Big sites tend to be really good at this guesswork: they can factor spell correction, personalization, and lots of business data into their guesses. Smaller and less tech-savvy sites tend to do a poorer job — if they have autocomplete at all.

What is it good for?

Autocomplete creates happier users in two measurable ways:

It finds their results faster. Every keystroke saved is a bonus for users. Speed matters, especially on mobile screens, where typing long search queries can be quite an ordeal.
It helps them find better results. Users don't always know what to type. They may know the concept they want but not the name, and they often make spelling mistakes and typos — as much as 10 to 20 percent of the time.

Datamuse Autocomplete

Datamuse Autocomplete, part of the Datamuse API, gives your search box an autocomplete function as smart and accurate as those used by the biggest sites. It can scale to inventories with millions of terms, and has many sophisticated enhancements:

Intelligent ranking by importance: Autocomplete puts the best suggestions first, based on how likely they are to lead the user to what they want.
Vocabulary optimization: Suggestions are tailored over time to the vocabulary nuances of your site, like inventory items and brand names.
Real-time spell correction: The system gracefully handles user errors of all kinds, including most misspellings and typos.

Autocomplete goes well beyond traditional spellcheck. It's built on more than a decade of analysis by Datamuse of how users spell their searches, and data-driven phonetic algorithms that match similar pronunciations. In most cases, a bad misspelling still produces helpful suggestions:
Live semantic re-mapping: Users who aren't deeply familiar with your inventory may not know the right words to search for. When that leads to poor search results (or none at all) users may leave your site in frustration. If a user has typed letters that don't seem to match an inventory entry, the Datamuse API looks for suggestions from your inventory that have similar meaning, using Datamuse's celebrated reverse dictionary technology.
Fast integration: Just add a snippet of Javascript code to the page that contains your search box, and (optionally) another snippet to your search results page to teach the system which searches are good. That's it: you're ready to go! A secure (HTTPS) endpoint is supported.
High performance: The Datamuse API serves a high rate of requests at low latency and with 99.99% uptime. Server-side latency is under 1 millisecond at the 99th percentile. The API is served from multiple datacenters to reduce the roundtrip time between our servers and your users around the globe. The vocabulary (inventory) size can scale to millions of terms.

Who's using it now?

The autocomplete service was originally developed to serve the top-ranked dictionary websites RhymeZone and OneLook. It is also used by Smashwords.com, the world's largest independent e-book distributor. You can try our autocomplete service by typing a query into the search boxes of any of these sites.

Interested in autocomplete for your website?

This service will be free to the first several sites to sign up as we build out the features of this service. To learn more, please contact Datamuse and tell us about your site or mobile application, your needs, and how much traffic you expect.

Request more information

Please describe your application, API needs, and expected traffic.

Note: If you have autocomplete already, chances are you're using a plugin that came with your search software (such as Apache Solr, Elastic Search, or Lucene) or a home-grown system. Either way, we'd be interested in hearing how well it is working for you and what improvements you would like to see.