Reverse token filteredit

Reverses each token in a stream. For example, you can use the reverse filter to change cat to tac.

Reversed tokens are useful for suffix-based searches, such as finding words that end in -ion or searching file names by their extension.

This filter uses Lucene’s ReverseStringFilter.


The following analyze API request uses the reverse filter to reverse each token in quick fox jumps:

GET _analyze
  "tokenizer" : "standard",
  "filter" : ["reverse"],
  "text" : "quick fox jumps"

The filter produces the following tokens:

[ kciuq, xof, spmuj ]

Add to an analyzeredit

The following create index API request uses the reverse filter to configure a new custom analyzer.

PUT reverse_example
  "settings" : {
    "analysis" : {
      "analyzer" : {
        "whitespace_reverse" : {
          "tokenizer" : "whitespace",
          "filter" : ["reverse"]