Gradio

Warnings

• breaking gr.update() was removed in Gradio 4.0. The entire pattern of returning gr.Textbox.update(value='x') or gr.update(visible=True) raises AttributeError. This is the #1 footgun from LLM-generated code using old Gradio docs.
  Fix: Return a component instance directly: return gr.Textbox(value='text', visible=True). For multiple outputs, return a tuple: return gr.Textbox(value='text'), gr.Button(visible=False)
• breaking Chatbot tuple format ([['user', 'assistant'], ...]) removed in Gradio 6.0. gr.Chatbot() and gr.ChatInterface() now require dict messages format: [{'role': 'user', 'content': '...'}, {'role': 'assistant', 'content': '...'}]
  Fix: Use type='messages' in gr.Chatbot(type='messages'). Format history as: [{'role': 'user', 'content': msg}, {'role': 'assistant', 'content': response}]
• breaking theme= parameter removed from gr.Blocks() in Gradio 6.0. TypeError: BlockContext.__init__() got an unexpected keyword argument 'theme'. Breaks all apps using gr.Blocks(theme=gr.themes.Soft()).
  Fix: Pass theme at the app level instead: demo = gr.Blocks(); demo.theme = gr.themes.Soft(). Or use theme in gr.Interface(theme=...).
• breaking concurrency_count parameter removed in Gradio 4.0. Per-event concurrency_limit replaced it. queue=False also removed — use concurrency_limit=None instead.
  Fix: Replace: demo.queue(concurrency_count=5) with per-event: btn.click(fn, ..., concurrency_limit=5). For unlimited: concurrency_limit=None.
• breaking In Gradio 5.0+, functions can only return files in the current working directory or temp directory. Returning absolute paths to arbitrary system files is blocked for security.
  Fix: Save output files to tempfile.NamedTemporaryFile() or the current working directory. Return the path from tempfile.
• gotcha Python 3.10 is now the minimum. Gradio 6.x will not install on Python 3.9.
  Fix: Upgrade to Python 3.10+. Pin gradio<5.0 for Python 3.9 environments.
• gotcha LLMs (including ChatGPT and Copilot) frequently generate Gradio 3.x code with gr.update() and tuple chatbot format that fails on 6.x. Always verify which Gradio version the generated code targets.
  Fix: When using AI to generate Gradio code, explicitly prompt: 'Use Gradio 6.x API — no gr.update(), use messages dict format for Chatbot.'

Install

• pip install gradio Standard

Imports

• gr.Interface

  import gradio as gr
  
  # Simple Interface (gr.update() is gone — return values directly)
  def greet(name, intensity):
      return 'Hello, ' + name + '!' * intensity
  
  demo = gr.Interface(
      fn=greet,
      inputs=[gr.Textbox(label='Name'), gr.Slider(1, 10, value=3)],
      outputs=gr.Textbox(label='Greeting')
  )
  demo.launch()

  gr.update() was removed in Gradio 4.0. Return component instances directly: return gr.Textbox(value='text', visible=True). Chatbot messages must use dict format in 6.0+: [{'role': 'user', 'content': 'Hello'}]

Quickstart

6.x API. Use type='messages' for gr.Chatbot. Return component instances, not gr.update().

import gradio as gr

# Simple Interface
def classify_text(text):
    return {'positive': 0.8, 'negative': 0.2}

gr.Interface(
    fn=classify_text,
    inputs=gr.Textbox(label='Input Text'),
    outputs=gr.Label(label='Sentiment')
).launch()


# Blocks API (more flexible)
def chat(message, history):
    # history is list of dicts: [{role, content}, ...]
    response = f'Echo: {message}'
    return response

with gr.Blocks() as demo:
    gr.Markdown('# My Chatbot')
    chatbot = gr.Chatbot(type='messages')  # dict format required in 6.0
    msg = gr.Textbox(label='Message')
    btn = gr.Button('Send')
    
    def respond(message, history):
        history.append({'role': 'user', 'content': message})
        history.append({'role': 'assistant', 'content': f'Echo: {message}'})
        return '', history
    
    btn.click(respond, [msg, chatbot], [msg, chatbot])

demo.launch(share=True)