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The Splainer!

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The sandbox that explains your search results for you so you don't have to go digging through explain debug! Paste in your Solr or Elasticsearch query URL and go. Try it out here.


You're a search developer trying to tune search results with Solr or Elasticsearch. You're engaged in search relevancy work.

You're probably stuck with the question of why? Why do search results come back in the order that they do? Solr and Elasticsearch exposes an explain syntax for you to try to explain search scoring. Unfortunately outside the simplest tasks, its a nightmare to read through. There are parsers like but they require a lot of manual copy/pasting of explain information to the tool.

Splainer is different by being a sandbox. Paste in your Solr or Elasticsearch URL, query parameters and all. As you work with your query, changing parameters, Splainer shows you parsed and summarized explain information alongside your documents. Continue working and see how the search results change.

Read the blog post introducing Splainer here

Splainer forms the core of the open source tool Quepid that allows you to do this over multiple queries against expert-graded search results to track search changes over a longer period of time.

Using Splainer

Take the tour to see how you'd use Splainer.

Using Splainer locally

We have a Docker image published at that you can use:

docker run -d -p 9000:9000 o19s/splainer and then go to http://localhost:9000

Splainer Package for Solr

We have a Solr Package of Splainer that is compatible with Solr 9+. Learn more in the solr-splainer-package

Developing Splainer

Npm/Yarn Dev Environment

Splainer is written using AngularJS project. It requires npm, grunt, and yarn.

Be sure you've installed npm, yarn, and grunt on your machine.

npm install -g grunt-cli

With Npm/Yarn installed

From the root of the project, you should be able to run the following:

grunt test
grunt serve

Now browse to http://localhost:9000.

To build the project, simply run grunt dist to build the static artifacts in the dist/ folder.

grunt dist

You can test out the static artifacts via ruby -run -e httpd -- -p 5000 ./dist and going to http://localhost:5000.

With Docker installed

From the root of the project, you should run:

docker build -t splainer  .
docker run -p 9000:9000 splainer:latest

or use the following shortcuts if you have ruby installed:

bin/docker b

then to run the server run

bin/docker s

Using docker-compose

From the root of the project,

docker-compose build
docker-compose run --rm --service-ports app

Using Docker Compose to test splainer-search with splainer

  • docker-compose.override.yml.example can be copied to docker-compose.override.yml and use it to override environment variables or work with a local copy of the splainer-search JS library during development defined in docker-compose.yml. Example is included. Just update the path to splainer-search with your local checkout!

Testing Notes

  • Unit tests are written using Karma.

  • The ./tests/splainer_test_links.html file is a list of links that invoke Splainer, both the local version and the deployed version against Solr and Elasticsearch, and is a great test to make sure the behavior hasn't reverted. Use this to make sure existing links still work!


Created by OpenSource Connections.

Thanks to all the community contributors for finding bugs and sharing fixes!.


Released under Apache 2