Why won't Microsoft Teams render an HTML file I uploaded?

Because Teams doesn't store it — the channel's Files tab is SharePoint, and SharePoint Online disables custom script on modern sites by default. An .html file stored there is handed back as a download rather than rendered as a page, so every viewer ends up opening a local copy with all the `file://` problems that implies.

What should I post in the channel instead?

A link to the published report. It opens in the browser for everyone in the channel, it's the same document for all of them, and comments land on the report rather than scrolling away in the channel.

Can I keep the report inside the company?

Yes. Set the report's visibility to your team or to signed-in users only, or gate it to your email domain — the channel link then only opens for people who pass that check. See sharing & access control.

Can a bot or pipeline post the report automatically?

Publish from CI with one PATCH so the URL stays stable, then have your existing Teams webhook post that URL. The message is one line and the report behind it is always the current run.

Does the interactive report still work?

Yes — report HTML renders with scripts enabled inside a sandboxed iframe, so filterable tables and charts behave the same way they do locally.

Share an HTML report in Microsoft Teams

Dragging report.html into a channel feels like the right move, and it is the one thing Teams handles worst.

Why the upload doesn't render

A channel's Files tab isn't Teams storage — it's a SharePoint document library. SharePoint Online disables custom script on modern sites by default, and an .html file living there is served as a download rather than rendered as a page. Teams shows a file card; the click produces a copy in someone's downloads folder.

From there it's the local-file problem in full: the assets folder didn't travel, fetch is blocked on the file:// origin, and on the Teams mobile app there's no sensible way to open it at all. See opening a local HTML file.

And you now have N copies in N downloads folders, one per person who clicked, each frozen at the moment they clicked it.

Post a link instead

Publish the report once:

curl -X POST https://commareports.com/api/v1/reports \
  -H "Authorization: Bearer $COMMA_API_TOKEN" \
  -H "Content-Type: application/json" \
  -d "$(jq -n --rawfile html report.html \
        '{title: "Nightly suite — main", html: $html, visibility: "registered"}')"

Paste the URL in the channel. It opens in the browser on desktop and in the Teams mobile app's web view, it's the same document for everyone, and it stays current when the report is refreshed.

Keeping it internal

A channel post is visible to the channel, but a link is a link — someone will forward it. The access check lives on the report, not on the message:

private — you and the report's team.
registered — any signed-in Comma user.
Domain gating and named reviewers for the "this stays inside the company" case.

Details in sharing & access control.

Automating the post

If the report comes out of a pipeline, PATCH the same report id every run so the URL never changes, then let your existing Teams incoming webhook post that one URL:

curl -fsS -X PATCH "https://commareports.com/api/v1/reports/$REPORT_ID" \
  -H "Authorization: Bearer $COMMA_API_TOKEN" \
  -H "Content-Type: application/json" \
  -d "$(jq -n --rawfile html report.html '{html: $html}')"

One stable link in the channel topic beats a new file card every night. More in publishing from CI.

Where the discussion goes

The reason a report in a chat channel decays is that the response to it is also in the chat channel — twenty messages down by the next morning. Anchored comments put the question on the row it's about, and it's still there on the next run.

Try it

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

Publish a report for your channel →