The Terraform Diagram as Code Generator turns a pasted Terraform configuration into a Mermaid diagram, so you can visualize resources and the references between them without leaving your browser. Each resource becomes a node, and whenever one resource refers to another, such as a bucket referencing aws_s3_bucket.this.id, an edge is drawn between the two nodes.
The generator parses your .tf with a built-in HCL parser, so there is no need to install Terraform or graphviz. The output is plain Mermaid text that you can drop into any Mermaid editor, a GitHub Markdown code block, or a documentation site. Because everything runs locally, your configuration is never uploaded and no cloud account is required. It is a quick way to explain a module to a teammate, to sanity-check that references line up the way you expect, or to include a diagram in a README that updates as the code changes.
Diagrams also help during incident response and onboarding. When something breaks, a current graph of resource relationships lets an on-call engineer see what depends on what without reading hundreds of lines of HCL. New teammates can grasp the shape of a system in seconds, and the visual makes gaps, such as an unreferenced security group, easy to notice at a glance. Because the diagram is regenerated from the code, it never drifts from reality the way a hand-drawn picture eventually does.
For larger systems the graph doubles as a review aid. Reviewers can skim the node and edge list to confirm that a proposed change only touches the resources it should, and that no unexpected cross-module dependency is being introduced. That context is hard to get from a diff alone, especially when resources are defined far apart in the file tree.