draw.io for JIRA server is the best value diagramming plugin for self-hosted JIRA instances.

 

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<h3>Documentation</h3>
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<a href="https://answers.atlassian.com/tags/addon-com.mxgraph.jira.plugins.drawio"><div style="background-color:#E9F5BF;text-align: center;border-radius: 6px; margin-left: 0; margin-right: auto; border: 1px solid #DFF1A3; padding: 20px 20px 20px; width: 250px; margin-bottom: 30px;">
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<h3>Ask a question</h3>
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<a href="https://draw.uservoice.com/forums/266072-feature-requests"><div style="background-color:#E9F5BF;text-align: center;border-radius: 6px; margin-left: auto; margin-right: 0; border: 1px solid #DFF1A3; padding: 20px 20px 20px; width: 250px; margin-bottom: 30px;">
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<h3>Feature request</h3>
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<a href="https://desk.draw.io/support/tickets/new"><div style="background-color:#E9F5BF;text-align: center;border-radius: 6px; margin-left: 0; margin-right: auto; border: 1px solid #DFF1A3; padding: 20px 20px 20px; width: 250px; margin-bottom: 30px;">
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<h3>Create Support Ticket</h3>
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