●Change8

Migrating to Streamlit 1.57.0

Version 1.57.0 introduces 4 breaking changes. This guide details how to update your code.

Released: 4/28/2026

4
Breaking Changes
2
Migration Steps
13
Affected Symbols

⚠️ Check Your Code

If you use any of these symbols, you need to read this guide:

plotly_chartvega_lite_chart_get_websocket_headersst.menu_buttonst.popoverAppTestst.alertst.Appst.bottomst.dataframest.data_editorst.radiost.text_area

Breaking Changes

●Issue #1

Starlette is now the default server; Tornado has been removed. Users relying on Tornado must switch to Starlette or another supported server.

●Issue #2

Deprecated keyword arguments have been removed from `plotly_chart` and `vega_lite_chart`.

●Issue #3

The internal function `_get_websocket_headers` has been removed.

●Issue #4

Direct conversion from polars to arrow now bypasses pandas.

Migration Steps

  1. 1
    If your application relied on Tornado as the server, you must update your configuration to use Starlette or another supported server.
  2. 2
    Review calls to `plotly_chart` and `vega_lite_chart` to remove any previously deprecated keyword arguments.

Release Summary

This release switches the default server to Starlette, removes Tornado, and introduces several new features like animated loading text (:shimmer[]) and the st.bottom container. Numerous bug fixes address compatibility with pandas 3.0+ and improve widget behavior.

Need More Details?

View the full release notes and all changes for Streamlit 1.57.0.

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