Leaving Slack? Check that your exported conversations will still be readable

A downloaded Slack export is a starting point. Before closing a workspace or changing access, check that the information you need is present and that you can read it outside Slack.

This guide is for people authorised to retain a workspace's public-channel conversations. ThreadKeep turns supported Slack public-channel JSON export ZIPs into searchable offline HTML archives. It works locally in your browser, without uploading your Slack messages or connecting to Slack.

1. Decide what you need to keep

Write down the channels, dates and conversations you expect to consult later. A project decision, its replies and a handover discussion are useful examples to check.

Also list anything you need beyond public-channel message text. ThreadKeep does not support private-channel or direct-message archives, recover deleted messages, or provide a complete-backup or compliance guarantee. If your task requires those things, its current scope will not meet the whole task.

Make sure you are authorised to export, retain and share the information. Having access to a conversation does not by itself settle those questions.

2. Obtain the available export while you still have access

Use Slack's export instructions to check the export options available to your workspace and role. ThreadKeep reads an existing supported export; it does not obtain one for you.

The content available for export depends on your plan and retention settings. A reader or converter cannot recreate messages absent from the export. Check the Slack import and export guide rather than assuming a ZIP contains everything ever posted.

Keep the original ZIP securely. Preserve it alongside any readable archive you create.

3. Treat attachment links separately from attachment files

A link to a PDF, photo or other attachment is not a saved copy of that file. ThreadKeep preserves supported attachment links but does not fetch or bundle the files. Those links may require Slack access or become unavailable later.

If particular files matter, retain them separately through an authorised process and check that the saved copies open. Do not close the original workspace on the assumption that a readable message archive includes its attachments.

4. Check compatibility before buying

Open the free local compatibility checker in desktop Chrome on Windows, ThreadKeep's initial supported platform. It checks your selected ZIP locally, reports counts, dates and omissions, and does not upload your file. No payment is required. The checker does not produce a downloadable message archive.

The main limits are 25 MiB per source ZIP and 25,000 included messages. Additional limits apply, including expanded size and record counts. Some legitimate Slack exports exceed them. Check the full published limits on the compatibility page; do not assume a small team necessarily has a small export.

Read the report, including its warnings. Compare the reported dates and counts with what you expected. Look for skipped records, reduced rich content and missing thread context. A successful check does not prove that an export is complete or authorised, or that every omission is acceptable for your purpose.

5. See whether the readable format suits your task

Try the synthetic archive demo. Every person and message in it is invented. Search for Thursday to see a matching reply displayed with its parent and other replies.

The demo shows the reading experience without asking you to share your own messages. Consider whether searchable message text, supported thread context, channels, people and timestamps cover the job you identified. ThreadKeep creates an archive to read; it does not import conversations into another chat service.

6. Save and inspect your archive before closing access

If your export is compatible, its omissions are acceptable and the offer fits, use the purchased converter to create and save the HTML archive. Reopen the downloaded file offline and try the representative conversations you listed earlier. Check important dates, replies and any missing-context warnings.

Your own review matters: a successful conversion is not a complete-backup guarantee. Retain the original export and any separately saved attachments. Protect the readable HTML as carefully as the source messages, and share it only with authorised recipients.

Check first, then decide

Check your export locally - free

ThreadKeep is A$79 once, including applicable Australian tax, for one organisation. It allows unlimited authorised exports within the published limits. Keep using your downloaded version, with 12 months of available maintenance updates within the purchased major version, email support and replacement downloads. Future major versions, lifetime updates, perpetual browser compatibility and a response-time SLA are not promised.

Full refund on request within 14 days; statutory rights remain unchanged. Review the final currency, tax and total at checkout and read the offer and licence.

ThreadKeep is supplied by Sky Tower. Questions: contact@lyramirae.com. Please do not email your export or message contents. ThreadKeep is not affiliated with or endorsed by Slack.