SKILL.md
$27
Input Widgets
Streamlit
marimo
Notes
st.slider()
mo.ui.slider()
st.select_slider()
mo.ui.slider(steps=[...])
Pass discrete values via steps
st.text_input()
mo.ui.text()
st.text_area()
mo.ui.text_area()
st.number_input()
mo.ui.number()
st.checkbox()
mo.ui.checkbox()
st.toggle()
mo.ui.switch()
st.radio()
mo.ui.radio()
st.selectbox()
mo.ui.dropdown()
st.multiselect()
mo.ui.multiselect()
st.date_input()
mo.ui.date()
st.time_input()
mo.ui.text()
No dedicated time widget
st.file_uploader()
mo.ui.file()
Use .contents() to read bytes
st.color_picker()
mo.ui.text(value="#000000")
No dedicated color picker
st.button()
mo.ui.button() or mo.ui.run_button()
Use run_button for triggering expensive computations
st.download_button()
mo.download()
Returns a download link element
st.form() + st.form_submit_button()
mo.ui.form(element)
Wraps any element so its value only updates on submit
Display Elements
Streamlit
marimo
Notes
st.write()
mo.md() or last expression
st.markdown()
mo.md()
Supports f-strings: mo.md(f"Value: {x.value}")
st.latex()
mo.md(r"$...$")
marimo uses KaTeX; see references/latex.md
st.code()
mo.md("python\n...\n")
st.dataframe()
df (last expression)
DataFrames render as interactive marimo widgets natively; use mo.ui.dataframe(df) only for no-code transformations
st.table()
df (last expression)
Use mo.ui.table(df) if you need row selection
st.metric()
mo.stat()
st.json()
mo.json() or mo.tree()
mo.tree() for interactive collapsible view
st.image()
mo.image()
st.audio()
mo.audio()
st.video()
mo.video()
Charts
Streamlit
marimo
Notes
st.plotly_chart(fig)
fig (last expression)
Use mo.ui.plotly(fig) for selections
st.altair_chart(chart)
chart (last expression)
Use mo.ui.altair_chart(chart) for selections
st.pyplot(fig)
fig (last expression)
Use mo.ui.matplotlib(fig) for interactive matplotlib
Layout
Streamlit
marimo
Notes
st.sidebar
mo.sidebar([...])
Pass a list of elements
st.columns()
mo.hstack([...])
Use widths=[...] for column ratios
st.tabs()
mo.ui.tabs({...})
Dict of {"Tab Name": content}
st.expander()
mo.accordion({...})
Dict of {"Title": content}
st.container()
mo.vstack([...])
st.empty()
mo.output.replace()
st.progress()
mo.status.progress_bar()
st.spinner()
mo.status.spinner()
Context manager
Key Conceptual Differences
Execution Model
Streamlit reruns the entire script top-to-bottom on every interaction. Marimo uses a reactive cell DAG — only cells that depend on changed variables re-execute.
- No need for
st.rerun()— reactivity is automatic.
- No need for
st.stop()— structure cells so downstream cells naturally depend on upstream values.
State Management
Streamlit
marimo
st.session_state["key"]
Regular Python variables between cells
Callback functions (on_change)
Cells referencing widget.value re-run automatically
st.query_params
mo.query_params
Caching
Streamlit
marimo
@st.cache_data
@mo.cache
@st.cache_resource
@mo.persistent_cache
@mo.cache is the primary caching decorator — it works like functools.cache but is aware of marimo's reactivity. @mo.persistent_cache goes further by persisting results to disk across sessions, useful for expensive computations like model training.
Multi-Page Apps
Marimo offers two approaches for multi-page Streamlit apps:
- Single notebook with routing: Use
mo.routeswithmo.nav_menuormo.sidebarto build multiple "pages" (tabs/routes) inside one notebook.
- Multiple notebooks as a gallery: Run a folder of notebooks with
marimo run folder/to serve them as a gallery with navigation.
Deploying
marimo features molab to host marimo apps instead of the streamlit community cloud. You can generate an "open in molab" button via the add-molab-badge skill.
Custom components
streamlit has a feature for custom components. These are not compatible with marimo. You might be able to generate an equivalent anywidget via the marimo-anywidget skill but discuss this with the user before working on that.