diff --git a/blog.njk b/blog.njk
index ef60589..acd8622 100644
--- a/blog.njk
+++ b/blog.njk
@@ -11,9 +11,9 @@ permalink: "blog/{% if pagination.pageNumber > 0 %}page/{{ pagination.pageNumber
 <div class="h-feed">
   <div class="flex flex-wrap items-center gap-4 mb-2">
     <h1 class="text-2xl sm:text-3xl font-bold text-surface-900 dark:text-surface-100">Blog</h1>
-    {% set sparklineData = collections.posts | postingFrequency %}
-    {% if sparklineData %}
-    <img src="https://v1.sparkline.11ty.dev/{{ sparklineData }}/" alt="Posting frequency over the last 12 months" width="200" height="30" class="opacity-60 dark:invert dark:opacity-40" loading="lazy">
+    {% set sparklineSvg = collections.posts | postingFrequency %}
+    {% if sparklineSvg %}
+    <span class="opacity-60 dark:opacity-40 text-surface-500 dark:text-surface-400">{{ sparklineSvg | safe }}</span>
     {% endif %}
   </div>
   <p class="text-surface-600 dark:text-surface-400 mb-6 sm:mb-8">
diff --git a/eleventy.config.js b/eleventy.config.js
index a937c51..8315b69 100644
--- a/eleventy.config.js
+++ b/eleventy.config.js
@@ -456,7 +456,17 @@ export default function (eleventyConfig) {
         counts[11 - monthsAgo]++;
       }
     }
-    return counts.join(",");
+    const max = Math.max(...counts, 1);
+    const w = 200;
+    const h = 30;
+    const pad = 2;
+    const step = w / (counts.length - 1);
+    const points = counts.map((v, i) => {
+      const x = i * step;
+      const y = h - pad - ((v / max) * (h - pad * 2));
+      return `${x.toFixed(1)},${y.toFixed(1)}`;
+    }).join(" ");
+    return `<svg viewBox="0 0 ${w} ${h}" width="${w}" height="${h}" xmlns="http://www.w3.org/2000/svg" role="img" aria-label="Posting frequency over the last 12 months"><polyline fill="none" stroke="currentColor" stroke-width="1.5" stroke-linecap="round" stroke-linejoin="round" points="${points}"/></svg>`;
   });
 
   // Collections for different post types