✨ Enable Spellcheck in Solr (Because Spelling Is Hard)

Enabling spellcheck in Apache Solr is like giving your users a helpful nudge whenever they make a typo—because we all know “seach” is not “search.”
Here’s how to get those “Did you mean...?” suggestions working for your queries!

📝 Step 1: Schema Configuration

1. Edit your schema.xml (in your Solr core's conf directory):
2. Define a field type for spellcheck:

<fieldType name="textSpell" class="solr.TextField" positionIncrementGap="100">
   <analyzer type="index">
       <tokenizer class="solr.StandardTokenizerFactory"/>
       <filter class="solr.LowerCaseFilterFactory"/>
   </analyzer>
   <analyzer type="query">
       <tokenizer class="solr.StandardTokenizerFactory"/>
       <filter class="solr.LowerCaseFilterFactory"/>
   </analyzer>
</fieldType>

3. Define your content field and a spellcheck field:

<field name="content" type="textSpell" indexed="true" stored="true"/>
<field name="spell" type="textSpell" indexed="true" stored="false" multiValued="true"/>

⚙️ Step 2: Solr Configuration

1. Edit your solrconfig.xml (in your Solr core's conf directory).
2. Find the <requestHandler> for /select and add the spellcheck component:

<requestHandler name="/select" class="solr.SearchHandler">
   <!-- ... -->
   <arr name="last-components">
       <str>spellcheck</str>
   </arr>
</requestHandler>

🔮 Step 3: Spellcheck Component Configuration

Still in solrconfig.xml, define your <searchComponent> for spellcheck:

<searchComponent name="spellcheck" class="solr.SpellCheckComponent">
   <lst name="spellchecker">
       <str name="name">default</str>
       <str name="field">spell</str>
       <str name="classname">solr.DirectSolrSpellChecker</str>
       <str name="distanceMeasure">internal</str>
       <float name="accuracy">0.5</float>
       <int name="maxEdits">2</int>
       <int name="minPrefix">1</int>
       <int name="maxInspections">5</int>
       <int name="minQueryLength">3</int>
       <float name="maxQueryFrequency">0.5</float>
   </lst>
</searchComponent>

Pro tip: You can tune these parameters based on your data and performance needs. For instance, more "maxEdits" means more generous suggestions, but potentially more noise!

♻️ Step 4: Reindex Your Data

After any schema/config changes, reindex your content.
Otherwise, your spellcheck dictionary will be lonely and unhelpful.

🧑‍💻 Step 5: Querying with Spellcheck

When making a search query, simply add the spellcheck parameter:

/select?q=your_query&spellcheck=true

You’ll get spellcheck suggestions in your Solr response, usually under the "spellcheck" section.
Voilà! No more missed searches due to typos. 🎉

💡 Bonus Tips

• Spellcheck is a game-changer for user experience—but don’t overdo it. Too many suggestions can be distracting.
• Always test with real-world typo examples (we all have a user who types "bannana" instead of "banana").
• Tweak your spellchecker for speed vs. accuracy—there’s always a balance.

Now your Solr is smart enough to fix “teh” into “the.” Happy searching! 🪄