MiniSearch
is a tiny but powerful in-memory fulltext search engine for
JavaScript. It is respectful of resources, and it can comfortably run both in
Node and in the browser.
Try out the demo application.
MiniSearch
addresses use cases where full-text search features are needed
(e.g. prefix search, fuzzy search, boosting of fields), but the data to be
indexed can fit locally in the process memory. While you may not index the whole
Wikipedia with it, there are surprisingly many use cases that are served well by
MiniSearch
. By storing the index in local memory, MiniSearch
can work
offline, and can process queries quickly, without network latency.
A prominent use-case is search-as-you-type features in web and mobile applications, where keeping the index on the client-side enables fast and reactive UI, removing the need to make requests to a search server.
-
Memory-efficient index, designed to support memory-constrained use cases like mobile browsers.
-
Exact, prefix, and fuzzy search
-
Auto-suggestion engine, for auto-completion of search queries
-
Documents can be added and removed from the index at any time
-
Simple API, providing building blocks to build specific solutions
-
Zero external dependencies, small and well tested code-base
With npm
:
npm install --save minisearch
With yarn
:
yarn add minisearch
Then require
or import
it in your project.
// A collection of documents for our examples
const documents = [
{ id: 1, title: 'Moby Dick', text: 'Call me Ishmael. Some years ago...' },
{ id: 2, title: 'Zen and the Art of Motorcycle Maintenance', text: 'I can see by my watch...' },
{ id: 3, title: 'Neuromancer', text: 'The sky above the port was...' },
{ id: 4, title: 'Zen and the Art of Archery', text: 'At first sight it must seem...' },
// ...and more
]
let miniSearch = new MiniSearch({ fields: ['title', 'text'] })
// Index all documents
miniSearch.addAll(documents)
// Search with default options
let results = miniSearch.search('zen art motorcycle')
// => [ { id: 2, score: 2.77258, match: { ... } }, { id: 4, score: 1.38629, match: { ... } } ]
MiniSearch
supports several options for more advanced search behavior:
// Search only specific fields
miniSearch.search('zen', { fields: ['title'] })
// Boost some fields (here "title")
miniSearch.search('zen', { boost: { title: 2 } })
// Prefix search (so that 'moto' will match 'motorcycle')
miniSearch.search('moto', { prefix: true })
// Fuzzy search, in this example, with a max edit distance of 0.2 * term length,
// rounded to nearest integer. The mispelled 'ismael' will match 'ishmael'.
miniSearch.search('ismael', { fuzzy: 0.2 })
// You can set the default search options upon initialization
miniSearch = new MiniSearch({
fields: ['title', 'text'],
searchOptions: {
boost: { title: 2 },
fuzzy: 0.2
}
})
miniSearch.addAll(documents)
// It will now by default perform fuzzy search and boost "title":
miniSearch.search('zen and motorcycles')
MiniSearch
can suggest search queries given an incomplete query:
miniSearch.autoSuggest('zen ar')
// => [ { suggestion: 'zen archery art', terms: [ 'zen', 'archery', 'art' ], score: 1.73332 },
// { suggestion: 'zen art', terms: [ 'zen', 'art' ], score: 1.21313 } ]
The autoSuggest
method takes the same options as the search
method, so you
can get suggestions for misspelled words using fuzzy search:
miniSearch.autoSuggest('neromancer', { fuzzy: 0.2 })
// => [ { suggestion: 'neuromancer', terms: [ 'neuromancer' ], score: 1.03998 } ]
By default, documents and queries are tokenized splitting on non-alphanumeric
characters (accented characters and other diacritics are considered
alphanumeric). No stop-word list is applied, but single-character words are
excluded. The tokenization logic can be easily changed by passing a custom
tokenizer function as the tokenize
option:
let stopWords = new Set(['and', 'or', 'to', 'in', 'a', 'the', /* ...and more */ ])
// Tokenize splitting by space and apply a stop-word list
let miniSearch = new MiniSearch({
fields: ['title', 'text'],
tokenize: (string) => string.split(/\s+/).filter(word => !stopWords.has(word))
})
Terms are downcased by default. No stemming is performed. To customize how the
terms are processed upon indexing or searching, for example to normalize them or
to apply stemming, the processTerm
option can be used:
const removeAccents = (term) =>
term.replace(/[àá]/, 'a')
.replace(/[èé]/, 'e')
.replace(/[ìí]/, 'i')
.replace(/[òó]/, 'o')
.replace(/[ùú]/, 'u')
// Perform custom term processing (here removing accents)
let miniSearch = new MiniSearch({
fields: ['title', 'text'],
processTerm: (term) => removeAccents(term.toLowerCase())
})
Refer to the API documentation for details about configuration options and methods.
MiniSearch
natively supports all modern browsers implementing JavaScript
standards, but requires a polyfill when used in Internet Explorer, as it makes
use functions like Object.entries
, Array.includes
, and Array.from
, which
are standard but not available on older browsers. The
@babel/polyfill
is one such
polyfill that can be used to provide those functions.