SingleFile · dev-docs

SingleFile: Overview

A practical introduction to SingleFile as a low-friction local web-page capture tool for portable, hashable OSINT evidence artifacts.

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overview
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Aug 22, 2026

SingleFile: Overview

SingleFile is a browser-based and command-line tool for saving a web page into a single self-contained HTML file.

Its value is simple:

preserve a portable local representation of the page you are looking at now.

That makes SingleFile especially useful for lightweight OSINT evidence capture.

Why a single file matters

Ordinary browser "Save Page" workflows can create:

page.html
page_files/

with many dependent resources.

That is inconvenient for:

  • case folders;
  • hashing;
  • backup;
  • transfer;
  • long-term organization.

SingleFile packages the page into one HTML artifact that is easier to:

  • name;
  • move;
  • hash;
  • store;
  • reopen;
  • attach to an evidence record.

What it is good for

Use SingleFile when you need:

  • immediate local capture of a public page;
  • a low-friction record before content changes;
  • an offline copy;
  • a portable artifact for an investigation;
  • a page file that can be hashed and referenced by evidence ID.

It works particularly well in an investigator workflow such as:

observe → save → record URL/time → continue research.

What SingleFile is not

SingleFile is not automatically:

  • a third-party historical archive;
  • a case-management system;
  • a complete network capture;
  • proof that the page is authentic;
  • proof that every dynamic resource was preserved perfectly.

The artifact is a representation created by the capture process.

Its evidentiary value depends on the surrounding provenance.

Pair the file with metadata

For an important capture, record at least:

source URL
capture timestamp
evidence ID
SingleFile version/method where relevant
SHA-256
short observation note

The filename alone is not enough.

Dynamic pages

Modern websites can depend on:

  • JavaScript;
  • login state;
  • cookies;
  • geolocation;
  • API calls;
  • personalization.

A SingleFile capture represents the page state available to the capture process.

Do not assume it represents every possible user experience.

If dynamic behavior matters, preserve additional evidence such as:

  • screenshot;
  • browser/network observation;
  • source page metadata;
  • a second capture method.

SingleFile versus archive systems

SingleFile is primarily a capture mechanism.

ArchiveBox, for example, can use SingleFile as one of several archival capture formats while also managing collections, schedules and other output types.

Wayback Machine solves another problem: third-party historical preservation.

SingleFile is strongest when the immediate question is:

Can I preserve this page locally right now?

References

last published Aug 22, 2026