Looker Studio Function : LEFT_TEXT
LEFT_TEXT Function in Looker Studio – Practical Guide with Examples
Category: Text Function
The LEFT_TEXT function in Looker Studio is a text manipulation function used to extract a specific number of characters from the left side of a text value. It is extremely useful when dealing with structured text fields like order IDs, product codes, invoice numbers, phone numbers, or date strings stored as text.
In many real projects, raw data is not always clean or well-formatted. For example, an order ID might contain region code + year + serial number in a single field. Instead of fixing this at the data source level, LEFT_TEXT allows analysts to quickly extract meaningful parts directly inside Looker Studio.
From a reporting perspective, this function helps create new dimensions, simplify grouping logic, and improve dashboard readability. Since LEFT_TEXT works at row level, it performs efficiently even on large datasets. It is commonly used along with other text functions like RIGHT_TEXT, MID, and CONCAT for advanced text transformations.
Overall, LEFT_TEXT is a simple yet powerful function that every Looker Studio user should know, especially when working with structured or semi-structured text data.
Purpose of the LEFT_TEXT Function
1. Extract Fixed-Length Codes
Used to extract region codes, category codes, or prefixes from text fields.
2. Data Cleaning
Helps clean raw text data by separating meaningful information.
3. Custom Dimension Creation
Allows creation of new calculated dimensions based on part of a text field.
4. Simplify Reporting Logic
Reduces dependency on complex formulas or source-level data changes.
Type of Calculation & Practical Use Cases
1. Calculated Dimension
LEFT_TEXT is mainly used as a calculated dimension.
2. Text Transformation
Helps transform raw text into business-friendly values.
3. Grouping & Categorization
Used for grouping data based on extracted text values.
4. Pre-Analysis Data Preparation
Acts as a lightweight data preparation step inside Looker Studio.
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LEFT_TEXT(text, number_of_characters)
LEFT_TEXT Function – Parameters Table
| Parameter | Type | Description |
|---|---|---|
| text | Text | The text value from which characters are extracted |
| number_of_characters | Number | Number of characters to extract from the left |
How Does the LEFT_TEXT Function Work?
The LEFT_TEXT function starts reading the text value from the leftmost character and extracts the number of characters specified in the second parameter. The function returns the extracted portion as a new text value.
For example, if the text is “IND-2025-001” and the number of characters is 3, the output will be “IND”. The function works on each row independently, making it reliable for large datasets. If the number of characters exceeds the text length, the entire text is returned without error.
When Should You Use LEFT_TEXT Function?
When extracting prefixes or fixed-length codes
When working with structured text fields
When creating new grouping dimensions
When data cleaning is needed inside Looker Studio
When avoiding source-level data changes
Examples of LEFT_TEXT Function
Example 1: Extract Country Code
LEFT_TEXT(Order_ID, 3)
Input: IND2025001
Output: IND
Example 2: Get Year from Text Date
LEFT_TEXT(Date_Text, 4)
Input: 2025-01-15
Output: 2025
Example 3: Product Category Code
LEFT_TEXT(Product_Code, 2)
Input: EL4589
Output: EL
Tips & Best Practices
Always verify text length before extraction
Use LEFT_TEXT only when text structure is consistent
Combine with RIGHT_TEXT or MID for complex logic
Test results using tables before finalizing dashboards
Keep calculated fields simple and readable
No, it simply extracts characters and does not compare values.
The full text is returned without any error.
No. Numbers must be converted to text first.
It is mainly used as a calculated dimension.
For fixed-length extraction, yes. For dynamic patterns, REGEXP is better.