diff --git a/wasm/app/app.js b/wasm/app/app.js
index c666f30..a312297 100644
--- a/wasm/app/app.js
+++ b/wasm/app/app.js
@@ -219,18 +219,12 @@ function runOnTierInWorker(tier, src, onLoading) {
             if (e.data.runId !== myRunId) return;
             if (e.data.kind === "loading") {
                 onLoading && onLoading(e.data.tier);
-            } else if (e.data.kind === "chunk") {
-                // First chunk spawns the in-progress block; subsequent
-                // chunks append to it. User sees displays land
-                // immediately, not just at the end of the run.
-                // Worker splits chunks on \n at the source and sends
-                // each line with an eol flag — re-attach the newline
-                // here so liveBlock.append still walks bytes looking
-                // for charCodeAt 10 and stacks per line. Avoids any
-                // unknown-quantity newline loss between Module.print
-                // and the main thread.
+            } else if (e.data.kind === "chunk-text") {
                 if (!liveBlock) liveBlock = startLiveBlock(tier);
-                liveBlock.append(e.data.chunk + (e.data.eol ? "\n" : ""));
+                liveBlock.appendText(e.data.text);
+            } else if (e.data.kind === "chunk-eol") {
+                if (!liveBlock) liveBlock = startLiveBlock(tier);
+                liveBlock.appendNewline();
             } else if (e.data.kind === "done") {
                 w.removeEventListener("message", handler);
                 workerState.pending[tier] = null;
@@ -285,23 +279,22 @@ function startLiveBlock(tierName) {
     let pendingText = "";
 
     return {
-        append(chunk) {
-            if (!chunk) return;
-            let start = 0;
-            for (let i = 0; i < chunk.length; i++) {
-                if (chunk.charCodeAt(i) === 10) {
-                    pendingText += chunk.slice(start, i);
-                    pendingLine.textContent = pendingText || " ";
-                    pendingText = "";
-                    pendingLine = makeLine();
-                    pre.appendChild(pendingLine);
-                    start = i + 1;
-                }
-            }
-            if (start < chunk.length) {
-                pendingText += chunk.slice(start);
-                pendingLine.textContent = pendingText;
-            }
+        appendText(t) {
+            // Pure text chunk — never contains a newline. Append to
+            // the in-progress line.
+            if (!t) return;
+            pendingText += t;
+            pendingLine.textContent = pendingText;
+            outputEl.scrollTop = outputEl.scrollHeight;
+        },
+        appendNewline() {
+            // End-of-line event — close the current line (with a
+            // single-space placeholder when empty so the row is
+            // visible) and spawn a fresh pending line below.
+            pendingLine.textContent = pendingText || " ";
+            pendingText = "";
+            pendingLine = makeLine();
+            pre.appendChild(pendingLine);
             outputEl.scrollTop = outputEl.scrollHeight;
         },
         finalize(elapsedMs, kind, fullOutput) {
diff --git a/wasm/app/worker.mjs b/wasm/app/worker.mjs
index c729a5c..f0d9c28 100644
--- a/wasm/app/worker.mjs
+++ b/wasm/app/worker.mjs
@@ -58,26 +58,32 @@ self.onmessage = async (e) => {
             // re-add the line break.
             (chunk) => {
                 if (!chunk) return;
+                // Split on \n at the source and post TWO separate
+                // message kinds: chunk-text (visible bytes, never
+                // containing a newline) and chunk-eol (a bare event
+                // marking end-of-line). Newlines no longer travel
+                // as bytes — they're typed messages. Whatever was
+                // eating the \n between Module.print and the DOM
+                // in fox's tab is bypassed.
                 let start = 0;
                 for (let i = 0; i < chunk.length; i++) {
                     if (chunk.charCodeAt(i) === 10) {
-                        self.postMessage({
-                            kind: "chunk",
-                            runId,
-                            tier,
-                            chunk: chunk.slice(start, i),
-                            eol: true,
-                        });
+                        if (i > start) {
+                            self.postMessage({
+                                kind: "chunk-text",
+                                runId, tier,
+                                text: chunk.slice(start, i),
+                            });
+                        }
+                        self.postMessage({ kind: "chunk-eol", runId, tier });
                         start = i + 1;
                     }
                 }
                 if (start < chunk.length) {
                     self.postMessage({
-                        kind: "chunk",
-                        runId,
-                        tier,
-                        chunk: chunk.slice(start),
-                        eol: false,
+                        kind: "chunk-text",
+                        runId, tier,
+                        text: chunk.slice(start),
                     });
                 }
             },
diff --git a/www/playground/app.js b/www/playground/app.js
index c666f30..a312297 100644
--- a/www/playground/app.js
+++ b/www/playground/app.js
@@ -219,18 +219,12 @@ function runOnTierInWorker(tier, src, onLoading) {
             if (e.data.runId !== myRunId) return;
             if (e.data.kind === "loading") {
                 onLoading && onLoading(e.data.tier);
-            } else if (e.data.kind === "chunk") {
-                // First chunk spawns the in-progress block; subsequent
-                // chunks append to it. User sees displays land
-                // immediately, not just at the end of the run.
-                // Worker splits chunks on \n at the source and sends
-                // each line with an eol flag — re-attach the newline
-                // here so liveBlock.append still walks bytes looking
-                // for charCodeAt 10 and stacks per line. Avoids any
-                // unknown-quantity newline loss between Module.print
-                // and the main thread.
+            } else if (e.data.kind === "chunk-text") {
                 if (!liveBlock) liveBlock = startLiveBlock(tier);
-                liveBlock.append(e.data.chunk + (e.data.eol ? "\n" : ""));
+                liveBlock.appendText(e.data.text);
+            } else if (e.data.kind === "chunk-eol") {
+                if (!liveBlock) liveBlock = startLiveBlock(tier);
+                liveBlock.appendNewline();
             } else if (e.data.kind === "done") {
                 w.removeEventListener("message", handler);
                 workerState.pending[tier] = null;
@@ -285,23 +279,22 @@ function startLiveBlock(tierName) {
     let pendingText = "";
 
     return {
-        append(chunk) {
-            if (!chunk) return;
-            let start = 0;
-            for (let i = 0; i < chunk.length; i++) {
-                if (chunk.charCodeAt(i) === 10) {
-                    pendingText += chunk.slice(start, i);
-                    pendingLine.textContent = pendingText || " ";
-                    pendingText = "";
-                    pendingLine = makeLine();
-                    pre.appendChild(pendingLine);
-                    start = i + 1;
-                }
-            }
-            if (start < chunk.length) {
-                pendingText += chunk.slice(start);
-                pendingLine.textContent = pendingText;
-            }
+        appendText(t) {
+            // Pure text chunk — never contains a newline. Append to
+            // the in-progress line.
+            if (!t) return;
+            pendingText += t;
+            pendingLine.textContent = pendingText;
+            outputEl.scrollTop = outputEl.scrollHeight;
+        },
+        appendNewline() {
+            // End-of-line event — close the current line (with a
+            // single-space placeholder when empty so the row is
+            // visible) and spawn a fresh pending line below.
+            pendingLine.textContent = pendingText || " ";
+            pendingText = "";
+            pendingLine = makeLine();
+            pre.appendChild(pendingLine);
             outputEl.scrollTop = outputEl.scrollHeight;
         },
         finalize(elapsedMs, kind, fullOutput) {
diff --git a/www/playground/worker.mjs b/www/playground/worker.mjs
index c729a5c..f0d9c28 100644
--- a/www/playground/worker.mjs
+++ b/www/playground/worker.mjs
@@ -58,26 +58,32 @@ self.onmessage = async (e) => {
             // re-add the line break.
             (chunk) => {
                 if (!chunk) return;
+                // Split on \n at the source and post TWO separate
+                // message kinds: chunk-text (visible bytes, never
+                // containing a newline) and chunk-eol (a bare event
+                // marking end-of-line). Newlines no longer travel
+                // as bytes — they're typed messages. Whatever was
+                // eating the \n between Module.print and the DOM
+                // in fox's tab is bypassed.
                 let start = 0;
                 for (let i = 0; i < chunk.length; i++) {
                     if (chunk.charCodeAt(i) === 10) {
-                        self.postMessage({
-                            kind: "chunk",
-                            runId,
-                            tier,
-                            chunk: chunk.slice(start, i),
-                            eol: true,
-                        });
+                        if (i > start) {
+                            self.postMessage({
+                                kind: "chunk-text",
+                                runId, tier,
+                                text: chunk.slice(start, i),
+                            });
+                        }
+                        self.postMessage({ kind: "chunk-eol", runId, tier });
                         start = i + 1;
                     }
                 }
                 if (start < chunk.length) {
                     self.postMessage({
-                        kind: "chunk",
-                        runId,
-                        tier,
-                        chunk: chunk.slice(start),
-                        eol: false,
+                        kind: "chunk-text",
+                        runId, tier,
+                        text: chunk.slice(start),
                     });
                 }
             },