Summary

• This PR introduces support for rendering Korean and Japanese characters correctly in GIFs generated by gif.py.

Problem

• Korean texts are garbled when rendering GIF.
• Simply adding Korean fonts to the fonts array has some limitations
  • Scenario: Suppose Chinese fonts have higher priority than Korean fonts. Both Chinese and Korean fonts are installed on the machine, and the user wants to render Korean text. -> Using Chinese font for Korean text, therefore texts are garbled.

Solution

• To resolve this, this PR implements a language detection mechanism using regular expressions. A dedicated font array is now defined for each language (Korean and Japanese). When rendering text, its language is first detected, and the corresponding font set is used, ensuring correct character display.

Known Issues & Limitations

• This solution has been confirmed to work for Korean and Japanese on macOS (with default English/Korean support).
• Chinese text still appears garbled. The root cause for this is not yet identified. However, it's hypothesized that this might be an environment-specific issue, as an observation from issue fixed Chinese Characters Garbled in GIFs Generated by Pillow on macOS #1885 suggests a user on a Chinese system is able to use the feature successfully.
• This PR conflicts with fixed Chinese Characters Garbled in GIFs Generated by Pillow on macOS #1885. However, the changes made in fixed Chinese Characters Garbled in GIFs Generated by Pillow on macOS #1885 are a complete subset of the changes included in this PR. Merging this PR should resolve the issue addressed in fixed Chinese Characters Garbled in GIFs Generated by Pillow on macOS #1885 as well.

Screenshots

Test Script

from langchain_google_genai import ChatGoogleGenerativeAI
from browser_use import Agent
from dotenv import load_dotenv
load_dotenv()

import asyncio

llm = ChatGoogleGenerativeAI(model="gemini-2.5-flash-preview-05-20")

prompt_gif_test_korean = """
당신은 QA 엔지니어입니다. google.com에 방문해 화면이 잘 나오는지 확인하세요. 그리고 종료하세요.
"""

prompt_gif_test_japanese = """
あなたはQAエンジニアです。 google.comにアクセスして、画面が正常に表示されるか確認してください。そして、終了してください。
"""

prompt_gif_test_chinese = """
你是一名QA工程师。访问google.com. 检查屏幕是否正常显示。然后关闭。
"""

async def main():
    agent = Agent(
        task=prompt_gif_test_japanese,
        llm=llm,
        generate_gif=True,
    )
    result = await agent.run()
    print(result)

asyncio.run(main())

Summary by cubic

Added support for Korean and Japanese fonts in GIF rendering by detecting text language and selecting the correct font, so characters display properly.

• New Features
  • Detects Korean, Japanese, and Chinese text using regular expressions.
  • Chooses a dedicated font set for each language to prevent garbled text.