# How To Open an HTML File on iPhone or Android

Canonical: https://commareports.com/open-html-file-on-iphone
Published: 2026-08-29

> Mail and Files won't render an .html attachment on a phone — you get raw markup or a download with nowhere to go. What actually works on iOS and Android, and the one fix that works on both.

# Opening an HTML file on a phone

Someone emailed you `report.html`. On a laptop you'd double-click it. On a
phone, you get one of these:

- Mail shows the **raw markup** as text.
- A download that lands somewhere no app will open.
- It opens, and it's **blank** or unstyled.

## Why it's awkward on iOS

iOS Mail deliberately doesn't render `.html` attachments — a mail client
executing markup from an arbitrary sender is a bad idea, and Apple treats
it as one. The workaround that mostly works:

1. Tap the attachment.
2. **Share → Save to Files.**
3. Open the Files app and tap the saved file. Safari renders it.

That gets you a single, self-contained page. It does not get you a real
report, because a file opened this way has an **opaque `file://` origin**:

- `fetch()` and `XMLHttpRequest` to a neighbouring file are blocked.
- `<script type="module">` won't load — module fetches follow CORS rules
  even locally.

Any report that loads its results as JSON at view time — Vitest's HTML
reporter is the well-known example — renders as an empty shell no matter
what you do on the phone.

## Why it's awkward on Android

Download the file, open the Files app, tap it, and Chrome will usually
offer to render it. Usually. Plenty of Android builds have no default
handler registered for local `text/html` and the tap simply does nothing,
and the ones that do work hit the exact same `file://` restrictions.

## The blank-page cause you can't fix on the device

Most tools that produce "an HTML report" produce a **directory** —
`index.html` plus a sibling folder of CSS, JavaScript and JSON. Playwright,
Allure, `genhtml`, `nbconvert`, Sphinx and Storybook all do.

Email one file out of that folder and every reference in it points at
something that isn't there. No amount of Save-to-Files fixes a missing
stylesheet. See [why the report lost its CSS](/html-report-broken-css).

## The fix: read a URL, not a file

Whoever has the report on a desktop drags the file — or the whole output
folder, or a zip — into [Comma](https://commareports.com/) and sends the
link instead:

- `index.html` becomes the report body, assets upload alongside it, and
  relative references are rewritten to the uploaded copies.
- Scripts run inside a sandboxed iframe (`allow-scripts`, no
  `allow-same-origin`), so interactive reports stay interactive — on a
  phone too. See [interactive HTML reports](/interactive-html-reports).

It opens in mobile Safari or Chrome like any other page. Nothing to
download, nothing to save, nothing to have an app for.

## If you're the one sending it

Send the link the first time. The attachment costs the recipient three
steps on a laptop and usually defeats them on a phone — and the moment
there are two recipients, there are two copies and no way to point at the
same paragraph. See [email an HTML report](/email-html-report) and
[stop screenshotting reports](/stop-screenshotting-reports).

## Is it safe to open?

Treat an `.html` attachment like any file from that sender — it can carry
scripts, and opening it locally runs them on your device. Comma renders
uploaded report HTML inside a sandboxed iframe with no same-origin access,
so a script in a report can't reach your session, cookies or storage. That
is a containment boundary, not a malware scanner: don't publish files from
senders you don't trust.

## Try it

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

**[Turn the file into a link →](https://commareports.com/)**

### Related

- [Someone sent me an HTML file](/open-html-file-online) — the desktop version
- [Why the report lost its CSS](/html-report-broken-css)
- [Email an HTML report](/email-html-report) · [Host an HTML file](/host-html-file)
- [Google Drive won't render HTML](/share-html-file-google-drive)