How do I open an HTML email attachment on iPhone?

Short answer

To open an HTML email attachment on iPhone, tap the attachment to preview it, then use the Share button to send it to HTML Keep. If your mail app doesn't offer that, save the attachment to Files first and share it from there. The attachment then opens as a real page, and a local copy stays where you can find it later.

Why the attachment preview falls short

Mail apps on iPhone show attachments in a quick preview. For HTML files that preview often skips JavaScript and may not display the page's full styling, so an interactive report or form can look empty.

Common examples are exported analytics reports, test results from a build tool, booking confirmations, invoices, newsletters saved as files, and course material sent by a teacher.

For a simple page with mostly text, the preview may be enough. When it looks blank, unstyled or frozen, that's the cue to open it properly.

Another reason to move it out of the inbox: attachments are easy to lose in a long thread, and a saved copy is quicker to reopen when you need the report again next week.

Open it from Apple Mail

1. Install HTML Keep from the App Store (download page).
2. In Mail, tap the .html attachment to open its preview.
3. Tap the Share button and choose HTML Keep. If it isn't in the app row, scroll or tap More.
4. The page opens with its scripts and layout working, and is saved as a project in your library.

Gmail, Outlook and other mail apps

Third-party mail apps place their buttons differently, and labels change between versions. Look for an option on the attachment such as share, open in, or a download arrow.

If the app only lets you save, save the attachment to the Files app. Then open Files, touch and hold the file, tap Share, and choose the viewer.

• Attachment arrived as a ZIP: share the ZIP instead. It unpacks into its own project so CSS, images and scripts keep working, and if there are several HTML pages you can switch between them.
• Attachment ends in .htm: that's still HTML and opens the same way as an .html file.
• The message body itself is HTML (a formatted email): that is just how the email is displayed, not a file you need to open.
• Attachment won't download: check your connection and try again, since large attachments may still be loading from the mail server.

Stay safe with HTML attachments

HTML files can contain scripts and forms, and phishing emails sometimes use them to imitate a sign-in page. Only open HTML attachments from senders you know and trust, and be wary of unexpected ones.

Never type a password into a page that arrived as an attachment. A legitimate service will ask you to sign in on its own website or app, not inside a downloaded file.

If an attachment claims to be urgent, such as an unpaid invoice from a company you don't recognize, check with the sender through a channel you already use before opening it.

After it's open

Once the attachment is saved locally you no longer need to search your inbox for it. Find it by name or by text inside the page, rename it, or set an icon.

If the page has a download button for a CSV or PDF, the file goes to the share sheet so you can save it. You can also export the page as PDF or print it, which helps when an invoice or report needs to be filed.

When the sender emails an updated report with the same file name, open it again and choose to update the existing project. For other ways files reach your phone, see opening HTML on iPhone.