Streamlit Cheat Sheet

01Install & Runcommand line

pip install streamlit★
Install the framework.
streamlit run first_app.py★
Launch the dev server & open browser.
import streamlit as st★
Universal import convention.
streamlit hello
Demo app to explore the API.
streamlit cache clear
Clear all on-disk/in-memory caches.
streamlit config show
Print all current config values.
streamlit docs / help / init / version
Open docs, get help, scaffold, or check version.

02Magic Commandsimplicit st.write

"_This_ is **Markdown**"★
A bare string on its own line renders.
my_variable
Any bare variable/expression auto-displays.
"dataframe:", my_df
Mixed bare-expression tuples render too.

03Display Textthe swiss-army function

st.write(obj)★
Auto-formats almost anything — df, error, chart...
st.write_stream(generator)
Stream tokens — built for LLM output.
st.markdown("_md_")★
Render Markdown / limited HTML.
st.title("…")★
Page-level title (H1).
st.header("…")
Section heading (H2).
st.subheader("…")
Sub-section heading (H3).
st.code("for i…")★
Syntax-highlighted code block.
st.latex(r"…")
Render LaTeX math.
st.text("…")
Fixed-width, no formatting.
st.badge("New")new
Small colored status pill.
st.html("<p>Hi!</p>")
Drop raw HTML into the page.
st.iframe(url, height=600)
Embed an external page.

04Display Datatables & numbers

st.dataframe(df)★
Interactive, sortable, scrollable table.
st.table(df.iloc[0:10])
Static table — fully rendered, no scroll.
st.json({"foo":"bar"})
Collapsible, syntax-highlighted JSON.
st.metric("label", 42, 2)★
Big number + delta indicator (▲/▼).

05Display Mediaimages, audio, video

st.image("./header.png")★
Show an image from path, URL, or array.
st.logo("logo.jpg")
App logo, top-left of sidebar/header.
st.pdf("doc.pdf")new
Render a PDF inline.
st.audio(data)
Embed an audio player.
st.video(data)
Embed a video player.
st.video(data, subtitles="./s.vtt")
Video with subtitle track.

06Display Chartsbuilt-in & library wrappers

st.line_chart(df)★
Zero-config line chart from a dataframe.
st.bar_chart(df)★
Zero-config bar chart.
st.area_chart(df)
Zero-config area chart.
st.scatter_chart(df)
Zero-config scatter plot.
st.map(df)
Plot lat/lon points on a map.
st.plotly_chart(fig)★
Full interactive Plotly figure.
st.pyplot(fig)
Render a Matplotlib figure.
st.altair_chart / graphviz_chart / pydeck_chart / vega_lite_chart
Other supported chart libraries.
st.plotly_chart(df, on_select="rerun")new
Capture click/box-select as an event → triggers rerun.

07Sidebar & Bottompin elements outside the flow

st.sidebar.radio("…", [1,2])★
Call directly off st.sidebar.
with st.sidebar: …★
Or group several elements with "with".
st.bottom.chat_input("…")
Pin an element to the bottom bar.

08Columns & Tabsside-by-side layout

col1, col2 = st.columns(2)★
Two equal-width columns.
st.columns([3, 1, 1])
Custom relative widths — first is widest.
st.columns(2, vertical_alignment="bottom")
Align column contents to the bottom.
tab1, tab2 = st.tabs(["A","B"])★
Containers switched by clickable tabs.
with col1: st.radio(…)★
"with" notation works for columns & tabs.

09Expanders, Popovers & Placeholderscollapse, float, or replace

expand = st.expander("label")★
Collapsible container.
pop = st.popover("label")
Floating panel triggered by a button.
el = st.empty(); el.line_chart(…)★
Reserve a slot; later calls replace its content.
box = st.container(); box.write(…)
Insert elements out of code order.
st.container(horizontal=True)new
Flex container — children laid out in a row.
st.space("small")
Add vertical breathing room.

10Control Flowforms, pages, fragments

st.stop()
Halt script execution immediately.
st.rerun()★
Force an immediate rerun from the top.
st.switch_page("pages/x.py")
Programmatically navigate to another page.
pg = st.navigation([st.Page(…)]); pg.run()★
Define multi-page navigation in the entrypoint.
with st.form("id"): … st.form_submit_button()★
Batch widgets — no rerun until submit.
@st.dialog("Welcome!")
Decorate a function to open as a modal.
@st.fragment★
Rerun just this function, not the whole script.

11Interactive Widgetsuser input — the largest family

st.button("Click me")★
Returns True for one rerun on click.
st.download_button("…", data)
Click to download bytes/file.
st.link_button("…", url)
Button that opens a URL.
st.page_link("app.py", label="Home")
Link to another page in the app.
st.checkbox("I agree")★
Boolean toggle.
st.toggle("Enable")
Switch-style boolean.
st.radio("Pick one", [..])★
Single choice from a list.
st.selectbox("Pick one", [..])★
Single choice dropdown.
st.multiselect("Buy", [..])★
Multiple choices from a list.
st.pills("Tags", [..])
Tag-style single/multi select.
st.segmented_control("Filter", [..])
Segmented-button style choice.
st.slider("Pick a #", 0, 100)★
Numeric (or date) range slider.
st.select_slider("Size", [..])
Slider over discrete options.
st.text_input("First name")★
Single-line text box.
st.text_area("…")
Multi-line text box.
st.number_input("…", 0, 10)★
Numeric stepper.
st.date_input / time_input / datetime_input
Pickers for date, time, or both.
st.file_uploader("Upload CSV")★
Drag-and-drop file upload.
st.camera_input / audio_input
Capture a photo or voice recording.
st.color_picker("Pick")
Hex color picker.
st.feedback("thumbs")
Thumbs/star/face rating widget.
st.data_editor("Edit", data)★
Spreadsheet-like editable table.
st.menu_button("Export", options=[..])new
Dropdown of selectable actions.
st.pagination(10)new
Page-number navigator control.
val = st.slider("…", 1, 88)★
Every widget returns its current value.
st.slider("…", 0, 100, disabled=True)
Disable to remove interactivity.

12Chat-based AppsLLM-style UI

with st.chat_message("user"): st.write(..)★
Avatar + bubble container for one message.
st.chat_input("Say something")★
Sticky input bar, pinned to bottom.
with st.container(): st.chat_input(..)
Place the chat box inline instead.

13Mutate Data & Echo Codeupdate without a rerun

el = st.dataframe(df1); el.add_rows(df2)★
Append rows to an already-drawn table.
el = st.line_chart(df1); el.add_rows(df2)★
Append rows to an already-drawn chart.
with st.echo(): st.write(..)
Show the source code, then run it.

14Cachingsurvive the rerun

@st.cache_data★
Cache data — DataFrames, API responses, etc.
@st.cache_resource★
Cache objects — DB connections, ML models.
foo.clear(ref1)
Clear the cached entry for one set of args.
foo.clear()
Clear every cached entry for this function.
st.cache_data.clear()
Wipe all cached data app-wide.

15Progress & Statuskeep users informed

with st.spinner("In progress"): …★
Spinner while a block of code runs.
bar = st.progress(50); bar.progress(100)★
Updatable progress bar.
with st.status("Authenticating…") as s: …
Expandable, updatable status log.
st.toast("Warming up…")★
Brief, auto-dismissing notification.
st.success / info / warning / error★
Color-coded inline message boxes.
st.exception(e)
Pretty-printed traceback.
st.balloons() / snow()
Celebratory full-screen animation.

16Users, Data & Configauth, connections, options

if not st.user.is_logged_in: st.login("provider")
Built-in OIDC authentication.
st.logout()
End the user's session.
st.context.cookies / headers / locale / ip_address
Read request & browser context.
st.connection("db", type="sql")
Managed connection to SQL, Snowflake, etc.
st.set_page_config(layout="wide")★
Title, icon, layout — call once, first.
st.query_params[key]
Read/write the URL query string.
st.get_option / st.set_option
Read or set a config value at runtime.
app = st.App()new
Expose the underlying Starlette app.

streamlit cheat sheet

Composing layout containers

st.sidebar

st.columns([3,1,1])

st.tabs([...])

st.expander / st.popover

Worth memorizing