seddonym · seddonym · Jan 16, 2026 · Jan 2, 2026 · Jan 2, 2026 · Jan 13, 2026
diff --git a/AUTHORS.rst b/AUTHORS.rst
@@ -3,3 +3,4 @@ Authors
 =======
 
 * David Seddon - https://seddonym.me
+* Fabien Marty - https://fabien-marty.dev
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
@@ -1,6 +1,11 @@
 Changelog
 =========
 
+2.3 (not released yet)
+----------------------
+* Add --format option to control the output format.
+* Add --force-console option to force the use of the console output.
+
 2.2 (2025-12-12)
 ----------------
 

diff --git a/README.rst b/README.rst
@@ -64,6 +64,8 @@ There is currently only one command.
       --show-cycle-breakers  Identify a set of dependencies that, if removed,
                              would make the graph acyclic, and display them as
                              dashed lines.
+      --format [html|dot]    Output format (default to html).
+      --force-console        Force the use of the console output.
       --help                 Show this message and exit.
 
 Draw a graph of the dependencies within any installed Python package or subpackage.
@@ -119,4 +121,52 @@ within ``django.db.utils``.
 
 Here you can see that two of the dependencies are shown as a dashed line. If these dependencies were to be
 removed, the graph would be acyclic. To decide on the cycle breakers, Impulse uses the
-`nominate_cycle_breakers method provided by Grimp <https://grimp.readthedocs.io/en/stable/usage.html#ImportGraph.nominate_cycle_breakers>`_.
+`nominate_cycle_breakers method provided by Grimp <https://grimp.readthedocs.io/en/stable/usage.html#ImportGraph.nominate_cycle_breakers>`_.
+
+Output formats
+**************
+
+By default, Impulse renders the graph as an interactive HTML page and opens it in your browser.
+You can change the output format using the ``--format`` option.
+
+**HTML format (default)**
+
+.. code-block:: text
+
+    impulse drawgraph django.db --format html
+
+Generates an HTML page with an interactive graph visualization, including download links for SVG and PNG.
+This is the default format when no ``--format`` option is specified.
+
+**DOT format**
+
+.. code-block:: text
+
+    impulse drawgraph django.db --format dot
+
+Outputs the graph in `DOT format <https://graphviz.org/doc/info/lang.html>`_, which can be used with
+Graphviz or other tools that support this format. This is useful for custom rendering or integration
+with other systems.
+
+For example, to generate a PNG using Graphviz:
+
+.. code-block:: text
+
+    impulse drawgraph django.db --format dot | dot -Tpng -o graph.png
+
+Redirecting output
+******************
+
+When you redirect the output to a file or pipe it to another command, Impulse automatically switches
+from opening a browser to printing to the console:
+
+.. code-block:: text
+
+    impulse drawgraph django.db > graph.html
+
+If you want to force console output even when running interactively (e.g., for scripting purposes),
+use the ``--force-console`` flag:
+
+.. code-block:: text
+
+    impulse drawgraph django.db --force-console
diff --git a/justfile b/justfile
@@ -14,6 +14,38 @@ test:
     @uv run --with=google-cloud-audit-log impulse drawgraph google.cloud.audit
     @uv run impulse drawgraph grimp --show-import-totals
     @uv run --with=django impulse drawgraph django.db --show-cycle-breakers
+    @just test-output-redirection
+
+# Test output redirection (HTML and DOT formats)
+test-output-redirection:
+    #!/usr/bin/env bash
+    set -euo pipefail
+
+    # Create unique temporary files (using -t for macOS compatibility)
+    html_output=$(mktemp -t impulse_test.XXXXXX.html)
+    dot_output=$(mktemp -t impulse_test.XXXXXX.dot)
+    force_console_output=$(mktemp -t impulse_test.XXXXXX.html)
+    trap 'rm -f "$html_output" "$dot_output" "$force_console_output"' EXIT
+
+    echo "Testing HTML output redirection..."
+    uv run impulse drawgraph grimp > "$html_output"
+    grep -q '<!DOCTYPE html>' "$html_output"
+    grep -q 'digraph' "$html_output"
+    echo "HTML output redirection: OK"
+
+    echo "Testing DOT format output..."
+    uv run impulse drawgraph grimp --format=dot > "$dot_output"
+    grep -q 'digraph' "$dot_output"
+    # DOT format should not contain HTML tags
+    ! grep -q '<!DOCTYPE html>' "$dot_output"
+    echo "DOT format output: OK"
+
+    echo "Testing --force-console flag..."
+    uv run impulse drawgraph grimp --force-console > "$force_console_output"
+    grep -q '<!DOCTYPE html>' "$force_console_output"
+    echo "--force-console flag: OK"
+
+    echo "All output redirection tests passed!"
 
 
 # Run tests under all supported Python versions.
Original file line number	Diff line number	Diff line change
Expand Up		@@ -3,3 +3,4 @@ Authors
		=======

		* David Seddon - https://seddonym.me
		* Fabien Marty - https://fabien-marty.dev