# Jupyter Widgets Don't Render in the Exported HTML — Why, and What Actually Works

Canonical: https://commareports.com/fix/jupyter-widgets-not-rendering-in-html
Published: 2026-09-07

> ipywidgets, sliders and interactive output vanish from nbconvert HTML because the kernel is gone. What --embed-images and widget state save, what needs Voilà, and how to share the result.

# The widgets are gone from the export

The notebook is perfect in the browser. `jupyter nbconvert --to html`
produces a file where the sliders are missing, the dropdown is a blank
space, and the cell below it shows the output from whatever value
happened to be selected last — or nothing at all.

## The reason, in one sentence

**An `ipywidgets` widget is a view onto a Python object living in the
kernel.** The export has no kernel. There is nothing on the other end of
the slider.

This is not a bug and no flag fixes it in general, because "make this
static file recompute a Python callback" is not a thing a static file
can do.

## What you can actually keep

**Serialized widget state.** Jupyter can embed the widgets' last state
into the notebook, and `nbconvert` will then render them:

- In Jupyter Notebook: **Widgets → Save Notebook Widget State**, save,
  then convert.
- In JupyterLab: the same option under the settings for the notebook,
  or set `store_widget_state` in the config.

The result is widgets that _appear_, with their last values, and do not
respond to interaction. For a report showing "here is the analysis at
these parameters", that is often exactly enough.

**Everything that renders to plain JavaScript.** Plotly, Altair, Bokeh,
ECharts and friends do not need the kernel — they serialize the data and
the rendering code into the page. They survive the export intact, as
long as the library itself is embedded rather than pulled from a CDN
that might be blocked:

```python
fig.write_html(..., include_plotlyjs=True)   # Plotly
chart.save("chart.html", inline=True)        # Altair
```

If those come out blank, the cause is the library, not the kernel — see
[Plotly chart missing from the exported HTML](/fix/plotly-chart-not-showing-in-html).

**Images.** `--embed-images` inlines matplotlib output as data URIs so
the export is one self-contained file instead of an HTML plus a
`notebook_files/` directory that gets separated from it:

```bash
jupyter nbconvert --to html --embed-images analysis.ipynb
```

That single flag prevents the most common "my exported notebook lost all
its plots" report, which is really
[an entry file that travelled without its folder](/html-report-broken-css).

## When you genuinely need live widgets

Then you need a kernel, which means a server:

- **Voilà** renders the notebook as an app with a live kernel behind it.
  Real interactivity, real hosting — one process per viewer session, and
  an authentication story you have to build.
- **Panel**, **Streamlit**, **Gradio**, **Shiny** — same trade in
  different clothes.

Worth being honest about the choice: most notebook "reports" are read
once by three people who want the conclusion. Paying for a live kernel
per reader to preserve a slider that nobody moves is a bad trade. Export
at the parameters that matter, and if the reader wants different
parameters, they will ask — which is a conversation, not a server.

## Sharing the export

Once you have HTML, the remaining problem is delivery. `file://` copies
break XHR-loading outputs, email clients strip scripts
([why](/email-html-report)), and a 30 MB self-contained notebook is
awkward as an attachment.

Publish it and send a link. The charts stay interactive — scripts run in
a sandboxed iframe (`allow-scripts`, no `allow-same-origin`) — and the
reader can select the cell output they have a question about and ask it
there, anchored to that output, instead of quoting it into Slack
([comment on HTML](/comment-on-html)).

Re-running weekly? A [routine](/features/routines) can execute the
notebook on a cron and post the refreshed export as a new revision at
the same URL, so the link in the team doc is always current.

**Limits:** entry HTML 5 MB; assets 25 MB per file, 250 MB and 500 files
per report.

## Try it

Comma is free — unlimited reports, unlimited commenters, unlimited
revision history.

**[Publish a notebook export →](https://commareports.com/)**

### Related

- [Share a Jupyter notebook as HTML](/share-jupyter-notebook-html)
- [Share an nbconvert HTML export](/share-nbconvert-html)
- [Plotly chart missing from the export](/fix/plotly-chart-not-showing-in-html)
- [Share a Voilà notebook](/share-voila-notebook)