diff --git a/browsergym/core/src/browsergym/core/env.py b/browsergym/core/src/browsergym/core/env.py
index feeb3151..537cb2a6 100644
--- a/browsergym/core/src/browsergym/core/env.py
+++ b/browsergym/core/src/browsergym/core/env.py
@@ -30,7 +30,6 @@
 )
 from .spaces import AnyBox, AnyDict, Unicode
 from .task import AbstractBrowserTask
-from ..utils.obs import b64_to_pil
 
 logger = logging.getLogger(__name__)
 
@@ -123,7 +122,7 @@ def __init__(
                     )
                 ),
                 "goal": Unicode(min_length=0, max_length=TEXT_MAX_LENGTH),
-                "goal_data": AnyDict(),
+                "goal_object": gym.spaces.Sequence(AnyDict()),
                 "open_pages_urls": gym.spaces.Sequence(
                     Unicode(min_length=0, max_length=TEXT_MAX_LENGTH)
                 ),
@@ -267,14 +266,37 @@ def override_property(task, env, property):
         # setup the task
         task_goal, task_info = self.task.setup(page=self.page)
 
+        # process the task goal
+
+        # no goal specified
+        if task_goal is None:
+            goal = []
+        # convert text-only goal (legacy) to new format
+        elif isinstance(task_goal, str):
+            goal = [{"type": "text", "text": task_goal}]
+        # new format goal with multiple texts and images (OpenAI style)
+        elif isinstance(task_goal, list):
+            goal = task_goal
+        else:
+            raise ValueError(f"task_goal should be of type str or list, got {task_goal.__class__}")
+
         # initialize the chat
         self.chat.add_message(
             role="assistant",
             msg="Hi! I am your UI assistant, I can perform web tasks for you. What can I help you with?",
         )
 
-        # process the task goal
-        self.goal, self.goal_data = self._process_task_goal(task_goal, send_to_chat=True)
+        # send task goal (if any) to the chat
+        for message in goal:
+            match message["type"]:
+                case "text":
+                    self.chat.add_message(role="user", msg=message["text"])
+                case "image_url":
+                    self.chat.add_message(role="user_image", msg=message["image_url"])
+                case _:
+                    raise ValueError(
+                        f"Unknown message type {repr(message['type'])} in the task goal."
+                    )
 
         self._wait_dom_loaded()
 
@@ -498,13 +520,14 @@ def _get_obs(self):
 
         # if no goal has been set yet, try to extract it from the chat
         if not self.goal:
-            self.goal, self.goal_data = self._try_and_extract_goal_from_chat()
+            logger.warning(f"Empty goal, trying to extract goal from chat as a fallback.")
+            self.goal = self._try_and_extract_goal_from_chat()
 
         # obs is generic to all tasks
         obs = {
             "chat_messages": copy.deepcopy(self.chat.messages),
-            "goal": self.goal,
-            "goal_data": self.goal_data,
+            "goal": self._goal_to_text(self.goal),  # legacy goal, deprecated
+            "goal_object": self.goal,  # new goal format, liust of messages openai style
             "open_pages_urls": [page.url for page in self.context.pages],
             "active_page_index": np.asarray([self.context.pages.index(self.page)]),
             "url": self.page.url,
@@ -520,83 +543,34 @@ def _get_obs(self):
 
         return obs
 
-    def _process_task_goal(self, task_goal, send_to_chat: bool = False):
-        # no goal specified
-        if task_goal is None:
-            goal = ""
-            goal_data = {}
-
-        # text-only goal
-        elif isinstance(task_goal, str):
-            goal = task_goal
-            goal_data = {}
-
-            if send_to_chat:
-                self.chat.add_message(role="user", msg=task_goal)
-
-        # goal with text and images
-        elif isinstance(task_goal, dict):
-            goal = task_goal["text"]
-            goal_data = {
-                "image_urls": task_goal["image_urls"],
-                "image_paths": [],
-            }
-            # save images from the goal to files in a local directory
-            temp_dir = Path(tempfile.mkdtemp())
-            for image_i, image_url in enumerate(task_goal["image_urls"]):
-                # download remotely hosted images
-                if image_url.startswith("http"):
-                    image = Image.open(requests.get(image_url, stream=True).raw)
-                # decode base64-encoded images
-                elif image_url.startswith("data:image"):
-                    image = b64_to_pil(image_url)
-                else:
-                    raise ValueError(f"Unexpected image_url: {image_url}")
-                # write images to local files
-                format = image.format.lower()
-                image_path = temp_dir / f"input_image_{image_i}.{format}"
-                image.save(image_path)
-                # add image path to the goal
-                goal_data["image_paths"].append(image_path)
-
-            if send_to_chat:
-                for image_url in task_goal["image_urls"]:
-                    # send goal images to the chat
-                    self.chat.add_message(role="user_image", msg=image_url)
-                # send goal text to the chat, after the images
-                self.chat.add_message(role="user", msg=task_goal["text"])
-        else:
-            raise ValueError(f"task_goal should be of type str or dict, got {task_goal.__class__}")
-
-        return goal, goal_data
-
     def _try_and_extract_goal_from_chat(self):
         # as a fallback, when a task does not specify a goal, we try to convert the first chat message into a goal
-        first_user_message = None
-        first_user_images = []
+        goal = []
         for msg in self.chat.messages:
             # extract first user message as goal, if any
             if msg["role"] == "user":
-                first_user_message = msg["message"]
+                goal = [{"type": "text", "text": msg["message"]}]
                 break
-            # extract any user_image message present before as a goal image
-            elif msg["role"] == "user_image":
-                first_user_images.append(msg["message"])
-            else:
-                pass
 
-        # convert chat messages to a task_goal, if any
-        if first_user_message is None:
-            task_goal = None
-        elif not first_user_images:
-            task_goal = first_user_message
-        else:
-            task_goal = {
-                "text": first_user_message,
-                "image_urls": first_user_images,
-            }
-
-        # process the task_goal into a proper goal, if any
-        goal, goal_data = self._process_task_goal(task_goal=task_goal, send_to_chat=False)
+        return goal
+
+    def _goal_to_text(self, goal: list):
+        goal_text_strings = []
+        for message in goal:
+            match message["type"]:
+                case "text":
+                    goal_text_strings.append(message["text"])
+                case "image_url":
+                    if message["image_url"].startswith("data:image"):
+                        goal_text_strings.append(
+                            "image_url: " + message["image_url"][:30] + "... (truncated)"
+                        )
+                    else:
+                        goal_text_strings.append("image_url: " + message["image_url"])
+                case _:
+                    raise ValueError(
+                        f"Unknown message type {repr(message['type'])} in the task goal."
+                    )
+        goal_text = "\n".join(goal_text_strings)
 
-        return goal, goal_data
+        return goal_text
diff --git a/browsergym/core/src/browsergym/utils/obs.py b/browsergym/core/src/browsergym/utils/obs.py
index db37a386..1799cbb6 100644
--- a/browsergym/core/src/browsergym/utils/obs.py
+++ b/browsergym/core/src/browsergym/utils/obs.py
@@ -1,6 +1,4 @@
 import ast
-import base64
-import io
 import logging
 import numpy as np
 import PIL.Image
@@ -10,7 +8,6 @@
 
 from collections import defaultdict
 from bs4 import BeautifulSoup
-from typing import Literal
 
 from browsergym.core.constants import BROWSERGYM_ID_ATTRIBUTE as BID_ATTR
 from browsergym.core.constants import BROWSERGYM_VISIBILITY_ATTRIBUTE as VIS_ATTR
@@ -548,25 +545,3 @@ def prune_html(html):
     html = soup.prettify()
 
     return html
-
-
-def pil_to_b64(img: PIL.Image.Image, format: Literal["png", "jpeg"] = "png") -> str:
-    assert format in ("png", "jpeg")
-    with io.BytesIO() as image_buffer:
-        img.save(image_buffer, format=format.upper())
-        byte_data = image_buffer.getvalue()
-    img_b64 = base64.b64encode(byte_data).decode("utf-8")
-    img_b64 = f"data:image/{format};base64," + img_b64
-    return img_b64
-
-
-def b64_to_pil(img_b64: str) -> str:
-    if img_b64.startswith("data:image/png;base64,"):
-        img_b64 = img_b64.removeprefix("data:image/png;base64,")
-    elif img_b64.startswith("data:image/jpeg;base64,"):
-        img_b64 = img_b64.removeprefix("data:image/jpeg;base64,")
-    else:
-        raise ValueError(f"Unexpected base64 encoding: {img_b64}")
-    img_data = base64.b64decode(img_b64)
-    img = PIL.Image.open(io.BytesIO(img_data))
-    return img
diff --git a/browsergym/visualwebarena/src/browsergym/visualwebarena/task.py b/browsergym/visualwebarena/src/browsergym/visualwebarena/task.py
index 11608b17..a189945e 100644
--- a/browsergym/visualwebarena/src/browsergym/visualwebarena/task.py
+++ b/browsergym/visualwebarena/src/browsergym/visualwebarena/task.py
@@ -2,6 +2,7 @@
 import logging
 import playwright.sync_api
 import importlib.resources
+import pathlib
 import tempfile
 import requests
 
@@ -10,6 +11,7 @@
 from browsergym.core.task import AbstractBrowserTask
 
 from .instance import VisualWebArenaInstance
+from .utils import image_url_to_pil_image
 
 logger = logging.getLogger(__name__)
 
@@ -129,26 +131,60 @@ def setup(self, page: playwright.sync_api.Page) -> tuple[str, dict]:
                 if i < len(start_urls) - 1:
                     page = page.context.new_page()
 
-        # recover goal
-        goal = {
-            "text": self.config["intent"],
-            "image_urls": self.config.get("image", []),
-        }
-        # fix goal if needed
-        if goal["image_urls"] is None:
-            goal["image_urls"] = []
-        elif isinstance(goal["image_urls"], str):
-            goal["image_urls"] = [goal["image_urls"]]
+        # recover goal text
+        goal_text = self.config["intent"]
 
         # This note is present in some of webarena's agent prompts
         if self.with_na_hint:
-            goal[
-                "text"
-            ] += """\
+            goal_text += """\
 
 If you believe the task is impossible to complete, provide the answer "N/A".
 """
 
+        # recover goal image urls
+        image_urls = self.config.get("image", [])
+
+        # fix image list if needed
+        if image_urls is None:
+            image_urls = []
+        elif isinstance(image_urls, str):
+            image_urls = [image_urls]
+
+        # save goal images to local files in a temporary directory
+        image_paths = []
+        temp_dir = pathlib.Path(tempfile.mkdtemp())
+        for i, image_url in enumerate(image_urls):
+            # extract image content from url
+            image = image_url_to_pil_image(image_url)
+            # write image to local file
+            format = image.format.lower()
+            image_path = temp_dir / f"input_image_{i}.{format}"
+            image.save(image_path)
+            # add image path to the goal
+            image_paths.append(image_path)
+
+        # build an OpenAI-style structured goal
+        # textual goal first
+        goal = [{"type": "text", "text": goal_text}]
+        # then goal images
+        for i, (image_url, image_path) in enumerate(zip(image_urls, image_paths)):
+            goal.extend(
+                [
+                    # image description (id and filepath)
+                    {
+                        "type": "text",
+                        "text": f"Input image {i}/{len(image_urls)} below (local path: {repr(image_path)})",
+                    },
+                    # actual image (image_url)
+                    {
+                        "type": "image_url",
+                        "image_url": {
+                            "url": image_url,
+                        },
+                    },
+                ]
+            )
+
         return goal, {}
 
     def cheat(self, page: playwright.sync_api.Page, chat_messages: list[str]) -> None:
diff --git a/browsergym/visualwebarena/src/browsergym/visualwebarena/utils.py b/browsergym/visualwebarena/src/browsergym/visualwebarena/utils.py
new file mode 100644
index 00000000..abb80fbd
--- /dev/null
+++ b/browsergym/visualwebarena/src/browsergym/visualwebarena/utils.py
@@ -0,0 +1,20 @@
+import base64
+import io
+import PIL.Image
+import requests
+
+
+def image_url_to_pil_image(image_url: str) -> str:
+    if image_url.startswith("http"):
+        image_data = requests.get(image_url, stream=True).raw
+    elif image_url.startswith("data:image/png;base64,"):
+        image_data = base64.b64decode(image_url.removeprefix("data:image/png;base64,"))
+    elif image_url.startswith("data:image/jpeg;base64,"):
+        image_data = base64.b64decode(image_url.removeprefix("data:image/jpeg;base64,"))
+    else:
+        if image_url.startswith("data:image/"):
+            raise ValueError(f"Unexpected image encoding: {image_url}")
+        else:
+            raise ValueError(f"Unexpected image URL: {image_url}")
+    img = PIL.Image.open(io.BytesIO(image_data))
+    return img