enomoto celtislab

You are using a tag cloud of the standard, and you do not want to display tags that belong to the category not related to the article. 
Try this widget. 
Based on the category of the display article, this widget gets the tag from the article categories of related range. 
For the article there is no category of post page, etc., or by setting <code>all category</code>, <code>internal link article</code>, it displays the tag by examining the related category. 
If you check the ‘internal link article’, get a category from the internal links to articles.
Select Category related range
<ul>
<li>All Category (unrelated article)</li>
<li>Current article Category</li>
<li>Include child category tree</li>
<li>Include parent category tree</li>
<li>Include internal linked article Category</li>
<li>Exclude Category</li>
</ul>
Other parameters : Display format, Sort by, Order, Font size, Number of tags to display, …
<a href="http://celtislab.net/wp_plugin_DCTagCloud/" title="Documentation in Japanese" rel="nofollow ugc">日本語の説明</a>

DynamicCategoryTagCloud

Displays the tag cloud dynamically from related articles belonging to the category of the display article

honza.skypala

Standard installation of WordPress provides tags for posts and also Tag Cloud widget for 45 most common tags. Unfortunatelly there is no option to offer your web visitors list of all tags. And that is purpose of this plugin.
This plugin adds a link to the bottom of the Tag Cloud widget, which leads to a page displaying table of all tags from the website. This table consists of two columns, in the first one you find tag name, which also serves as a link to the articles tagged in it. The second column contains count, how many times the tag is used. The table is sortable by both columns, just by clicking on the header of the column. Sorting is provided by JavaScript, so no reloading of page.
<h3>License</h3>
WTFPL License 2.0 applies
<pre><code> DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
 Version 2, December 2004

Copyright (C) 2004 Sam Hocevar <sam@hocevar.net>

Everyone is permitted to copy and distribute verbatim or modified
copies of this license document, and changing it is allowed as long
as the name is changed.

 DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
 TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION

 0. You just DO WHAT THE FUCK YOU WANT TO.<h3>ToDo</h3>
</code></pre>
* compatibility with WordPress not using permalinks

Tags Page

As soon as I enabled this plugin my site was littered with PHP warnings. 
The dev has not checked for basic things like making sure variables are set before checking their value.
The one thing I expected this plugin to do was to make a list of tags as the url "/tags" but this did not work.
Coding standards seemed very poor with a lot of bad code smell. Zero separation of logic and templates.

Poor quality

Adds a table listing all tags registered on your website.

DynamicCategoryTagCloud vs Tags Page