Parameters are a powerful feature in Tableau — they enable dynamic controls, what-if scenarios, and interactive dashboards. But when it comes to usability, they often fall short, especially in how values are displayed to end users.
By default, parameter values are raw numbers, which can be hard to interpret by users. Whether you’re showing date ranges, filter types, or word lengths, poorly labeled parameters can make a dashboard feel clunky and inaccessible. In this post, I’ll show you a simple way to make a slider-parameter clearer, more intuitive, and more user-friendly.
Parameters are easy
I was building a dashboard for a highly valued client that involved displaying a lot of text. One of their requests was to add a feature allowing users to filter the text based on character count — specifically, to only show entries with at least n characters.
This functionality is easy within Tableau:
- Create a parameter which let the user choose a number between 0 and 1000
- Create a calculated field which filters the data with text shorter than the value of the parameter:
- Add the calculated field to the filter shelf, and you are ready – users can the parameter to select only data with at least n characters
Improving on the defaults
This parameter is quite basic and lacks guidance for users. What exactly does “Text Length” refer to? What does the number represent? And how should it be interpreted for texts with a maximum of 50 characters versus those with up to 5,000 characters?
Show only Sensible values
Start by displaying only relevant values—always beginning with 0. Avoid showing values that don’t make sense in context.
To achieve this, I created a calculated field that returns the length of the text, except when the value equals the minimum available length—in that case, it returns 0 instead.
This calculated field is used in the configuration of the parameter: Select ‘Allowable values – Range’, and select the calculated field on ‘Web workbook opens’
Select a sensible ‘Step size’: do users really need to be able to set every value, or are steps of 5 (10, 25, 100,…) enough?
Change the Title
Changing the title is always a good thing. Describe the functionality of the parameter:
is already much better.
Change the Display Format
The layout of the parameter can further by improved by adding the ‘units’ to the display format. If you add ” characters” (including the space) to the ‘Suffix’, the value-label of the parameter is much easier to read.
Better ‘zero’ values
I like the formatting of the parameter already a lot better – but what I don’t like is the label of ‘0’:
How can this be improved? By ‘abusing’ the Custom Format of the Display format!
The Custom Format had been discussed before (like on the post about custom formatting percentages ). This options makes it possible to create different formats for positive values, negative values, and zero (0) values.
I used this custom format for the parameter:
\A\t\ \l\e\a\s\t 0 characters;0;"All Word Lengths"Explanation:
- For the positive values above 0:
\A\t\ \l\e\a\s\t 0 characters
“At least ” in front of the value (‘0’ represents the value of the parameter). Every character has a ‘\’ in front of it, to avoid being misinterpreted as a special character like a date. This is called ‘escaping’ - ” characters” after the value (these don’t need to be escaped)
- Just show the negative values:
0 - If the value is 0:
"No Limit"
show the text ‘No Limit’.
It looks rather cryptic, but if you look close to it, it makes sense.
The result
A clean, easy-to-understand parameter, including a meaningful zero value.
Parameters may seem small, but improving them has a big impact on usability and user experience.
