---
title: Trim
description: Remove trailing and leading whitespace from a token
canonical: https://docs.paradedb.com/documentation/token-filters/trim
---

The trim filter removes leading and trailing whitespace from a token (but not whitespace in the middle). If a token consists
entirely of whitespace, the token is eliminated entirely.

This filter is useful for tokenizers that don't already split on whitespace, like the [literal normalized](/documentation/tokenizers/available-tokenizers/literal-normalized)
tokenizer or certain language-specific tokenizers.

```sql
CREATE INDEX search_idx ON mock_items
USING bm25 (id, (description::pdb.literal_normalized('trim=true')))
WITH (key_field='id');
```

To demonstrate this token filter, let's compare the output of the following two statements:

```sql
SELECT
  '    token with whitespace   '::pdb.literal_normalized::text[],
  '    token with whitespace   '::pdb.literal_normalized('trim=true')::text[];
```

```ini Expected Response
               text               |           text
----------------------------------+---------------------------
 {"    token with whitespace   "} | {"token with whitespace"}
(1 row)
```
