diff --git a/.changeset/fix-terminal-pty-sizing.md b/.changeset/fix-terminal-pty-sizing.md
new file mode 100644
index 0000000..0764929
--- /dev/null
+++ b/.changeset/fix-terminal-pty-sizing.md
@@ -0,0 +1,5 @@
+---
+"@jmfederico/pi-web": patch
+---
+
+Fix browser terminal sizing so progress/status lines update in place instead of wrapping when the PTY size has not caught up with the visible terminal.
diff --git a/src/client/src/api/sockets.ts b/src/client/src/api/sockets.ts
index c324448..c328033 100644
--- a/src/client/src/api/sockets.ts
+++ b/src/client/src/api/sockets.ts
@@ -6,8 +6,9 @@ export function globalSessionEvents(): WebSocket {
   return new WebSocket(`${webSocketBaseUrl()}/api/sessions/events`);
 }
 
-export function terminalSocket(projectId: string, workspaceId: string, terminalId: string): WebSocket {
-  return new WebSocket(`${webSocketBaseUrl()}/api/projects/${encodeURIComponent(projectId)}/workspaces/${encodeURIComponent(workspaceId)}/terminals/${encodeURIComponent(terminalId)}/socket`);
+export function terminalSocket(projectId: string, workspaceId: string, terminalId: string, initialSize?: { cols: number; rows: number }): WebSocket {
+  const sizeQuery = initialSize === undefined ? "" : `?cols=${encodeURIComponent(String(initialSize.cols))}&rows=${encodeURIComponent(String(initialSize.rows))}`;
+  return new WebSocket(`${webSocketBaseUrl()}/api/projects/${encodeURIComponent(projectId)}/workspaces/${encodeURIComponent(workspaceId)}/terminals/${encodeURIComponent(terminalId)}/socket${sizeQuery}`);
 }
 
 export function realtimeEvents(): WebSocket {
diff --git a/src/client/src/components/TerminalPanel.ts b/src/client/src/components/TerminalPanel.ts
index 69c004e..f4ea184 100644
--- a/src/client/src/components/TerminalPanel.ts
+++ b/src/client/src/components/TerminalPanel.ts
@@ -1,10 +1,20 @@
 import { css, html, LitElement } from "lit";
 import { customElement, property, query, state } from "lit/decorators.js";
-import { Terminal } from "@xterm/xterm";
-import { FitAddon } from "@xterm/addon-fit";
+import { Terminal, type ITerminalOptions } from "@xterm/xterm";
+import { FitAddon, type ITerminalDimensions } from "@xterm/addon-fit";
 import "@xterm/xterm/css/xterm.css";
 import { terminalSocket, terminalsApi, type TerminalInfo, type Workspace } from "../api";
 
+const TERMINAL_OPTIONS: ITerminalOptions = {
+  cursorBlink: true,
+  convertEol: true,
+  fontFamily: "ui-monospace, SFMono-Regular, Menlo, Consolas, monospace",
+  fontSize: 13,
+  theme: { background: "#05070a", foreground: "#e6edf3", cursor: "#58a6ff", selectionBackground: "#264f78" },
+};
+
+const DEFAULT_TERMINAL_SIZE: TerminalSize = { cols: 100, rows: 30 };
+
 @customElement("terminal-panel")
 export class TerminalPanel extends LitElement {
   @property({ attribute: false }) workspace: Workspace | undefined;
@@ -82,7 +92,8 @@ export class TerminalPanel extends LitElement {
     if (this.workspace === undefined) return;
     this.error = undefined;
     try {
-      const terminal = await terminalsApi.startTerminal(this.workspace.projectId, this.workspace.id, { cols: 100, rows: 30 });
+      const size = this.measureTerminalSize() ?? DEFAULT_TERMINAL_SIZE;
+      const terminal = await terminalsApi.startTerminal(this.workspace.projectId, this.workspace.id, size);
       this.terminals = [...this.terminals, terminal];
       this.selectTerminal(terminal.id);
     } catch (error) {
@@ -115,13 +126,7 @@ export class TerminalPanel extends LitElement {
   private ensureTerminalView(): void {
     const workspace = this.workspace;
     if (!this.visible || this.terminal !== undefined || this.selectedId === undefined || this.terminalHost === undefined || workspace === undefined) return;
-    const terminal = new Terminal({
-      cursorBlink: true,
-      convertEol: true,
-      fontFamily: "ui-monospace, SFMono-Regular, Menlo, Consolas, monospace",
-      fontSize: 13,
-      theme: { background: "#05070a", foreground: "#e6edf3", cursor: "#58a6ff", selectionBackground: "#264f78" },
-    });
+    const terminal = new Terminal(TERMINAL_OPTIONS);
     const fitAddon = new FitAddon();
     terminal.loadAddon(fitAddon);
     terminal.open(this.terminalHost);
@@ -134,13 +139,14 @@ export class TerminalPanel extends LitElement {
       const filtered = filterTerminalInput(data);
       if (filtered !== "") this.send({ type: "input", data: filtered });
     });
-    this.connectSocket(workspace.projectId, workspace.id, this.selectedId, terminal);
+    const initialSize = this.fitTerminal();
+    this.connectSocket(workspace.projectId, workspace.id, this.selectedId, terminal, initialSize);
     requestAnimationFrame(() => { this.fitAndNotify(); });
     terminal.focus();
   }
 
-  private connectSocket(projectId: string, workspaceId: string, terminalId: string, terminal: Terminal): void {
-    const socket = terminalSocket(projectId, workspaceId, terminalId);
+  private connectSocket(projectId: string, workspaceId: string, terminalId: string, terminal: Terminal, initialSize: TerminalSize | undefined): void {
+    const socket = terminalSocket(projectId, workspaceId, terminalId, initialSize);
     socket.binaryType = "arraybuffer";
     this.socket = socket;
     socket.addEventListener("open", () => { this.fitAndNotify(); });
@@ -180,9 +186,32 @@ export class TerminalPanel extends LitElement {
   }
 
   private fitAndNotify(): void {
-    if (this.fitAddon === undefined || this.terminal === undefined) return;
+    const size = this.fitTerminal();
+    if (size === undefined) return;
+    this.send({ type: "resize", ...size });
+  }
+
+  private fitTerminal(): TerminalSize | undefined {
+    if (this.fitAddon === undefined || this.terminal === undefined) return undefined;
+    const dimensions = this.fitAddon.proposeDimensions();
+    const size = terminalSizeFromDimensions(dimensions);
+    if (size === undefined) return undefined;
     this.fitAddon.fit();
-    this.send({ type: "resize", cols: this.terminal.cols, rows: this.terminal.rows });
+    return size;
+  }
+
+  private measureTerminalSize(): TerminalSize | undefined {
+    const currentSize = this.fitTerminal();
+    if (currentSize !== undefined) return currentSize;
+    if (this.terminal !== undefined || this.terminalHost === undefined) return undefined;
+
+    const measuringTerminal = new Terminal(TERMINAL_OPTIONS);
+    const measuringFitAddon = new FitAddon();
+    measuringTerminal.loadAddon(measuringFitAddon);
+    measuringTerminal.open(this.terminalHost);
+    const size = terminalSizeFromDimensions(measuringFitAddon.proposeDimensions());
+    measuringTerminal.dispose();
+    return size;
   }
 
   private send(message: { type: "input"; data: string } | { type: "resize"; cols: number; rows: number }): void {
@@ -249,6 +278,11 @@ export class TerminalPanel extends LitElement {
   `;
 }
 
+interface TerminalSize {
+  cols: number;
+  rows: number;
+}
+
 type ServerTerminalMessage =
   | { type: "output"; data: string; replay?: boolean }
   | { type: "exit"; exitCode?: number }
@@ -278,6 +312,15 @@ async function socketDataToString(data: unknown): Promise<string> {
   return String(data);
 }
 
+function terminalSizeFromDimensions(dimensions: ITerminalDimensions | undefined): TerminalSize | undefined {
+  if (dimensions === undefined || !isValidTerminalSize(dimensions.cols, dimensions.rows)) return undefined;
+  return { cols: Math.floor(dimensions.cols), rows: Math.floor(dimensions.rows) };
+}
+
+function isValidTerminalSize(cols: number, rows: number): boolean {
+  return Number.isFinite(cols) && Number.isFinite(rows) && cols > 0 && rows > 0;
+}
+
 function isRecord(value: unknown): value is Record<string, unknown> {
   return typeof value === "object" && value !== null;
 }
diff --git a/src/server/terminalProxyRoutes.ts b/src/server/terminalProxyRoutes.ts
index 1ec648d..bb620ac 100644
--- a/src/server/terminalProxyRoutes.ts
+++ b/src/server/terminalProxyRoutes.ts
@@ -1,9 +1,10 @@
 import type { FastifyInstance, FastifyReply } from "fastify";
-import { WebSocket, type RawData } from "ws";
 import type { ProjectService } from "./projects/projectService.js";
 import { SessionDaemonClient } from "./sessiond/sessionDaemonClient.js";
 import { resolveWorkspaceContext } from "./workspaces/workspaceContext.js";
 import type { WorkspaceService } from "./workspaces/workspaceService.js";
+import { terminalSizeQuery } from "./terminals/terminalSize.js";
+import { bridgeSockets } from "./webSocketBridge.js";
 
 export function registerTerminalProxyRoutes(app: FastifyInstance, projects: ProjectService, workspaces: WorkspaceService, daemon = new SessionDaemonClient()): void {
   app.get<{ Params: { projectId: string; workspaceId: string } }>("/api/projects/:projectId/workspaces/:workspaceId/terminals", async (request, reply) => {
@@ -36,10 +37,11 @@ export function registerTerminalProxyRoutes(app: FastifyInstance, projects: Proj
     }
   });
 
-  app.get<{ Params: { projectId: string; workspaceId: string; terminalId: string } }>("/api/projects/:projectId/workspaces/:workspaceId/terminals/:terminalId/socket", { websocket: true }, async (socket, request) => {
+  app.get<{ Params: { projectId: string; workspaceId: string; terminalId: string }; Querystring: { cols?: string; rows?: string } }>("/api/projects/:projectId/workspaces/:workspaceId/terminals/:terminalId/socket", { websocket: true }, async (socket, request) => {
     try {
       await resolveWorkspaceContext(projects, workspaces, request.params.projectId, request.params.workspaceId);
-      bridgeSockets(socket, daemon.connectWebSocket(`/terminals/${request.params.terminalId}/socket`));
+      const sizeQuery = terminalSizeQuery(request.query.cols, request.query.rows);
+      bridgeSockets(socket, daemon.connectWebSocket(`/terminals/${request.params.terminalId}/socket${sizeQuery}`));
     } catch (error) {
       socket.send(JSON.stringify({ type: "error", message: error instanceof Error ? error.message : String(error) }));
       socket.close();
@@ -60,15 +62,3 @@ function requestFailed(reply: FastifyReply, error: unknown): void {
   reply.code(400).send({ error: error instanceof Error ? error.message : String(error) });
 }
 
-function bridgeSockets(client: WebSocket, upstream: WebSocket): void {
-  client.on("message", (data) => { sendIfOpen(upstream, data); });
-  upstream.on("message", (data) => { sendIfOpen(client, data); });
-  client.on("close", () => { upstream.close(); });
-  upstream.on("close", () => { client.close(); });
-  upstream.on("error", () => { client.close(); });
-  client.on("error", () => { upstream.close(); });
-}
-
-function sendIfOpen(socket: WebSocket, data: RawData): void {
-  if (socket.readyState === WebSocket.OPEN) socket.send(data);
-}
diff --git a/src/server/terminals/terminalRoutes.test.ts b/src/server/terminals/terminalRoutes.test.ts
new file mode 100644
index 0000000..847f756
--- /dev/null
+++ b/src/server/terminals/terminalRoutes.test.ts
@@ -0,0 +1,92 @@
+import Fastify, { type FastifyInstance } from "fastify";
+import fastifyWebsocket from "@fastify/websocket";
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+import { WebSocket, type RawData } from "ws";
+import type { TerminalInfo } from "./terminalService.js";
+import { registerTerminalRoutes, type TerminalRouteService } from "./terminalRoutes.js";
+
+let app: FastifyInstance;
+let terminals: FakeTerminals;
+
+beforeEach(async () => {
+  app = Fastify({ logger: false });
+  await app.register(fastifyWebsocket);
+  terminals = new FakeTerminals();
+  registerTerminalRoutes(app, terminals);
+  await app.listen({ host: "127.0.0.1", port: 0 });
+});
+
+afterEach(async () => {
+  await app.close();
+});
+
+describe("terminal socket routes", () => {
+  it("applies the initial socket size before attaching and replaying output", async () => {
+    const socket = new WebSocket(`${serverUrl(app)}/terminals/t1/socket?cols=120.9&rows=40.2`);
+
+    await expect(nextMessage(socket)).resolves.toBe(JSON.stringify({ type: "output", data: "replayed", replay: true }));
+    expect(terminals.events).toEqual(["resize:t1:120x40", "attach:t1"]);
+
+    socket.close();
+  });
+});
+
+class FakeTerminals implements TerminalRouteService {
+  readonly events: string[] = [];
+
+  list(cwd: string): TerminalInfo[] {
+    void cwd;
+    return [];
+  }
+
+  create(options: { cwd: string; name?: string; cols?: number; rows?: number }): TerminalInfo {
+    return {
+      id: "t1",
+      cwd: options.cwd,
+      name: options.name ?? "Shell 1",
+      createdAt: "2026-05-13T00:00:00.000Z",
+      exited: false,
+    };
+  }
+
+  close(id: string): void {
+    this.events.push(`close:${id}`);
+  }
+
+  attach(id: string, handlers: { output: (data: string, replay: boolean) => void; exit: (exitCode: number | undefined) => void }): () => void {
+    this.events.push(`attach:${id}`);
+    handlers.output("replayed", true);
+    return () => {
+      this.events.push(`detach:${id}`);
+    };
+  }
+
+  write(id: string, data: string): void {
+    this.events.push(`write:${id}:${data}`);
+  }
+
+  resize(id: string, cols: number, rows: number): void {
+    this.events.push(`resize:${id}:${String(cols)}x${String(rows)}`);
+  }
+}
+
+function serverUrl(instance: FastifyInstance): string {
+  const address = instance.server.address();
+  if (address === null || typeof address === "string") throw new Error("Expected TCP server address");
+  return `ws://127.0.0.1:${String(address.port)}`;
+}
+
+function nextMessage(socket: WebSocket): Promise<string> {
+  return new Promise((resolve) => {
+    socket.once("message", (data) => {
+      resolve(rawDataToString(data));
+    });
+  });
+}
+
+function rawDataToString(data: RawData): string {
+  if (typeof data === "string") return data;
+  if (data instanceof ArrayBuffer) return Buffer.from(data).toString("utf8");
+  if (Array.isArray(data)) return Buffer.concat(data).toString("utf8");
+  return data.toString("utf8");
+}
diff --git a/src/server/terminals/terminalRoutes.ts b/src/server/terminals/terminalRoutes.ts
index c1709f5..2d20809 100644
--- a/src/server/terminals/terminalRoutes.ts
+++ b/src/server/terminals/terminalRoutes.ts
@@ -1,8 +1,18 @@
 import type { FastifyInstance } from "fastify";
 import type { RawData } from "ws";
-import type { TerminalService } from "./terminalService.js";
+import type { TerminalInfo } from "./terminalService.js";
+import { parseTerminalSize } from "./terminalSize.js";
 
-export function registerTerminalRoutes(app: FastifyInstance, terminals: TerminalService, prefix = ""): void {
+export interface TerminalRouteService {
+  list(cwd: string): TerminalInfo[];
+  create(options: { cwd: string; name?: string; cols?: number; rows?: number }): TerminalInfo;
+  close(id: string): void;
+  attach(id: string, handlers: { output: (data: string, replay: boolean) => void; exit: (exitCode: number | undefined) => void }): () => void;
+  write(id: string, data: string): void;
+  resize(id: string, cols: number, rows: number): void;
+}
+
+export function registerTerminalRoutes(app: FastifyInstance, terminals: TerminalRouteService, prefix = ""): void {
   app.get<{ Querystring: { cwd?: string } }>(`${prefix}/terminals`, (request, reply) => {
     if (request.query.cwd === undefined || request.query.cwd === "") return reply.code(400).send({ error: "cwd query parameter is required" });
     return terminals.list(request.query.cwd);
@@ -21,9 +31,11 @@ export function registerTerminalRoutes(app: FastifyInstance, terminals: Terminal
     return { closed: true };
   });
 
-  app.get<{ Params: { terminalId: string } }>(`${prefix}/terminals/:terminalId/socket`, { websocket: true }, (socket, request) => {
+  app.get<{ Params: { terminalId: string }; Querystring: { cols?: string; rows?: string } }>(`${prefix}/terminals/:terminalId/socket`, { websocket: true }, (socket, request) => {
     let detach: (() => void) | undefined;
     try {
+      const initialSize = parseTerminalSize(request.query.cols, request.query.rows);
+      if (initialSize !== undefined) terminals.resize(request.params.terminalId, initialSize.cols, initialSize.rows);
       detach = terminals.attach(request.params.terminalId, {
         output: (data, replay) => { socket.send(JSON.stringify({ type: "output", data, replay })); },
         exit: (exitCode) => { socket.send(JSON.stringify({ type: "exit", exitCode })); },
diff --git a/src/server/terminals/terminalSize.test.ts b/src/server/terminals/terminalSize.test.ts
new file mode 100644
index 0000000..1e98b65
--- /dev/null
+++ b/src/server/terminals/terminalSize.test.ts
@@ -0,0 +1,21 @@
+import { describe, expect, it } from "vitest";
+import { parseTerminalSize, terminalSizeQuery } from "./terminalSize.js";
+
+describe("terminal size helpers", () => {
+  it("normalizes valid terminal dimensions", () => {
+    expect(parseTerminalSize("120.9", "40.2")).toEqual({ cols: 120, rows: 40 });
+    expect(parseTerminalSize(80, 24)).toEqual({ cols: 80, rows: 24 });
+  });
+
+  it("rejects missing or invalid dimensions", () => {
+    expect(parseTerminalSize(undefined, "24")).toBeUndefined();
+    expect(parseTerminalSize("0", "24")).toBeUndefined();
+    expect(parseTerminalSize("80", "NaN")).toBeUndefined();
+    expect(parseTerminalSize("80", "-1")).toBeUndefined();
+  });
+
+  it("builds a normalized query string only for valid dimensions", () => {
+    expect(terminalSizeQuery("120.9", "40.2")).toBe("?cols=120&rows=40");
+    expect(terminalSizeQuery("invalid", "40")).toBe("");
+  });
+});
diff --git a/src/server/terminals/terminalSize.ts b/src/server/terminals/terminalSize.ts
new file mode 100644
index 0000000..f096578
--- /dev/null
+++ b/src/server/terminals/terminalSize.ts
@@ -0,0 +1,21 @@
+export interface TerminalSize {
+  cols: number;
+  rows: number;
+}
+
+export function parseTerminalSize(cols: string | number | undefined, rows: string | number | undefined): TerminalSize | undefined {
+  const parsedCols = Number(cols);
+  const parsedRows = Number(rows);
+  if (!isValidTerminalSize(parsedCols, parsedRows)) return undefined;
+  return { cols: Math.floor(parsedCols), rows: Math.floor(parsedRows) };
+}
+
+export function terminalSizeQuery(cols: string | number | undefined, rows: string | number | undefined): string {
+  const size = parseTerminalSize(cols, rows);
+  if (size === undefined) return "";
+  return `?cols=${encodeURIComponent(String(size.cols))}&rows=${encodeURIComponent(String(size.rows))}`;
+}
+
+export function isValidTerminalSize(cols: number, rows: number): boolean {
+  return Number.isFinite(cols) && Number.isFinite(rows) && cols > 0 && rows > 0;
+}
diff --git a/src/server/webSocketBridge.test.ts b/src/server/webSocketBridge.test.ts
new file mode 100644
index 0000000..43328a7
--- /dev/null
+++ b/src/server/webSocketBridge.test.ts
@@ -0,0 +1,66 @@
+import { afterEach, describe, expect, it } from "vitest";
+import { WebSocket, WebSocketServer, type RawData } from "ws";
+import { createBufferedSender } from "./webSocketBridge.js";
+
+let server: WebSocketServer | undefined;
+
+afterEach(async () => {
+  const socketServer = server;
+  if (socketServer === undefined) return;
+  await new Promise<void>((resolve) => {
+    socketServer.close(() => { resolve(); });
+  });
+  server = undefined;
+});
+
+describe("createBufferedSender", () => {
+  it("queues messages while a WebSocket is still connecting", async () => {
+    const socketServer = new WebSocketServer({ host: "127.0.0.1", port: 0 });
+    server = socketServer;
+    const connected = new Promise<WebSocket>((resolve) => {
+      socketServer.once("connection", resolve);
+    });
+    await waitForListening(socketServer);
+
+    const client = new WebSocket(serverUrl(socketServer));
+    const send = createBufferedSender(client);
+    send("queued-before-open");
+
+    const serverSocket = await connected;
+    await expect(nextMessage(serverSocket)).resolves.toBe("queued-before-open");
+    client.close();
+    serverSocket.close();
+  });
+});
+
+function waitForListening(socketServer: WebSocketServer): Promise<void> {
+  if (socketServer.address() !== null) return Promise.resolve();
+  return new Promise((resolve, reject) => {
+    socketServer.once("error", reject);
+    socketServer.once("listening", () => {
+      socketServer.off("error", reject);
+      resolve();
+    });
+  });
+}
+
+function serverUrl(socketServer: WebSocketServer): string {
+  const address = socketServer.address();
+  if (address === null || typeof address === "string") throw new Error("Expected TCP server address");
+  return `ws://127.0.0.1:${String(address.port)}`;
+}
+
+function nextMessage(socket: WebSocket): Promise<string> {
+  return new Promise((resolve) => {
+    socket.once("message", (data) => {
+      resolve(rawDataToString(data));
+    });
+  });
+}
+
+function rawDataToString(data: RawData): string {
+  if (typeof data === "string") return data;
+  if (data instanceof ArrayBuffer) return Buffer.from(data).toString("utf8");
+  if (Array.isArray(data)) return Buffer.concat(data).toString("utf8");
+  return data.toString("utf8");
+}
diff --git a/src/server/webSocketBridge.ts b/src/server/webSocketBridge.ts
new file mode 100644
index 0000000..342e7af
--- /dev/null
+++ b/src/server/webSocketBridge.ts
@@ -0,0 +1,31 @@
+import { WebSocket, type Data } from "ws";
+
+export function bridgeSockets(client: WebSocket, upstream: WebSocket): void {
+  const sendToClient = createBufferedSender(client);
+  const sendToUpstream = createBufferedSender(upstream);
+  client.on("message", (data) => { sendToUpstream(data); });
+  upstream.on("message", (data) => { sendToClient(data); });
+  client.on("close", () => { upstream.close(); });
+  upstream.on("close", () => { client.close(); });
+  upstream.on("error", () => { client.close(); });
+  client.on("error", () => { upstream.close(); });
+}
+
+export function createBufferedSender(socket: WebSocket): (data: Data) => void {
+  const queue: Data[] = [];
+  const flush = () => {
+    while (socket.readyState === WebSocket.OPEN) {
+      const data = queue.shift();
+      if (data === undefined) return;
+      socket.send(data);
+    }
+  };
+  socket.on("open", flush);
+  return (data) => {
+    if (socket.readyState === WebSocket.OPEN) {
+      socket.send(data);
+      return;
+    }
+    if (socket.readyState === WebSocket.CONNECTING) queue.push(data);
+  };
+}