diff --git a/.changeset/chilly-words-march.md b/.changeset/chilly-words-march.md
new file mode 100644
index 000000000..54c0b4ebf
--- /dev/null
+++ b/.changeset/chilly-words-march.md
@@ -0,0 +1,5 @@
+---
+'mermaid': patch
+---
+
+fix: Correct viewBox casing and make SVGs responsive
diff --git a/cypress/helpers/util.ts b/cypress/helpers/util.ts
index cf0e9a87d..d02e9da87 100644
--- a/cypress/helpers/util.ts
+++ b/cypress/helpers/util.ts
@@ -99,6 +99,7 @@ export const openURLAndVerifyRendering = (
   cy.visit(url);
   cy.window().should('have.property', 'rendered', true);
   cy.get('svg').should('be.visible');
+  cy.get('svg').should('not.have.attr', 'viewbox');
 
   if (validation) {
     cy.get('svg').should(validation);
diff --git a/packages/mermaid/src/diagrams/packet/renderer.ts b/packages/mermaid/src/diagrams/packet/renderer.ts
index 25445a228..95226cf12 100644
--- a/packages/mermaid/src/diagrams/packet/renderer.ts
+++ b/packages/mermaid/src/diagrams/packet/renderer.ts
@@ -16,7 +16,7 @@ const draw: DrawDefinition = (_text, id, _version, diagram: Diagram) => {
   const svgWidth = bitWidth * bitsPerRow + 2;
   const svg: SVG = selectSvgElement(id);
 
-  svg.attr('viewbox', `0 0 ${svgWidth} ${svgHeight}`);
+  svg.attr('viewBox', `0 0 ${svgWidth} ${svgHeight}`);
   configureSvgSize(svg, svgHeight, svgWidth, config.useMaxWidth);
 
   for (const [word, packet] of words.entries()) {
diff --git a/packages/mermaid/src/diagrams/radar/renderer.ts b/packages/mermaid/src/diagrams/radar/renderer.ts
index 7324a3a44..247ded66d 100644
--- a/packages/mermaid/src/diagrams/radar/renderer.ts
+++ b/packages/mermaid/src/diagrams/radar/renderer.ts
@@ -2,6 +2,7 @@ import type { Diagram } from '../../Diagram.js';
 import type { RadarDiagramConfig } from '../../config.type.js';
 import type { DiagramRenderer, DrawDefinition, SVG, SVGGroup } from '../../diagram-api/types.js';
 import { selectSvgElement } from '../../rendering-util/selectSvgElement.js';
+import { configureSvgSize } from '../../setupGraphViewbox.js';
 import type { RadarDB, RadarAxis, RadarCurve } from './types.js';
 
 const draw: DrawDefinition = (_text, id, _version, diagram: Diagram) => {
@@ -53,11 +54,9 @@ const drawFrame = (svg: SVG, config: Required<RadarDiagramConfig>): SVGGroup =>
     x: config.marginLeft + config.width / 2,
     y: config.marginTop + config.height / 2,
   };
-  // Initialize the SVG
-  svg
-    .attr('viewbox', `0 0 ${totalWidth} ${totalHeight}`)
-    .attr('width', totalWidth)
-    .attr('height', totalHeight);
+  configureSvgSize(svg, totalHeight, totalWidth, config.useMaxWidth ?? true);
+
+  svg.attr('viewBox', `0 0 ${totalWidth} ${totalHeight}`);
   // g element to center the radar chart
   return svg.append('g').attr('transform', `translate(${center.x}, ${center.y})`);
 };