How to download your Slack message history if you're not a channel admin
Slack isn't like email. It's not infinitely searchable and DM threads disappear if the other party leaves the company. Here's how to make sure you never lose evidence of those important details in your Slack threads.
Like almost anyone dealing with corporate teams, I spend a lot of time on Slack. But I'm not a Slack guru. I just chat on the channels I'm assigned by clients and partners. As such, I've never given much consideration to archiving and preserving conversational knowledge. It's just a part of my work day.
But recently one of the team members working for a client left the company. I will miss working with that person and wish the best for them. Today, when I went back to our private Slack direct message conversation thread, I found it to be missing. Because their account was no longer on Slack, their direct message thread was gone as well.
But that thread had a lot of important information, information I will need as I continue to provide services to the client. It had my marching orders for the next few months. It had discussions of useful resources and stats I need while providing services. It also had discussions about subject matter experts on the project, their expertise areas, and their roles. In other words, that message thread was valuable. It even had discussions of agreed-upon fees.
Without giving it much thought, I generally figured that the Slack message history would persist the way an email archive does. I always assumed I could go back in and look stuff up for reference whenever necessary. But I found it concerning that, when I looked at the Direct messages area on the left side of the Slack screen, I found that I could no longer see my history with this person.
How to find a message archive
As it turns out, there is a way to find the message archive. If you hit the little clock icon at the top of your screen, you can see a history of recent conversations.
Unfortunately, those conversations don't last on that list forever. Only the last few conversations remain available. Even if you tap Show more, message history is limited. Also, older conversations with accounts that haven't been on Slack for a month or so are no longer available. I confirmed this definitively because an extensive conversation thread with another client team member who left the project about six weeks ago is completely gone.
But, if you act quickly after an account is removed, you can find the archive in order to save it.
How to save a Slack message archive
Slack does allow you to export and save a message archive, but only if you are the channel owner or admin. That said, there are ways -- even if you're not a channel superuser -- to grab all the history of a given message thread. These approaches are not particularly elegant, but they do work.
Save archive using cut, paste, and Word
The first approach captures your entire message thread text into a Word document, which you can then save, turn into a PDF, or otherwise archive. Theoretically, you could use another word processor, but I tested it with Word. You want to use something that saves rich text, so that images, emojis, and links are preserved as well.
In Slack, select the message thread you want to save.
Scroll to the very beginning, and left-click on the very first word of text.
Scroll to the bottom of the thread, hold down your shift key, and click after the last word.
Go up to the Edit menu, select Copy.
Switch to a blank Word document and click paste.
Save it and you have an editable, searchable, clickable archive.
The only downside of this approach is that the final saved archive won't look exactly like it does in Slack. To fix that, try this next approach.
Save archive using scrolling screenshot software
This approach takes a screenshot of the entire message thread, even if you have to scroll for page after page. To accomplish this, you'll want to use software that can capture a scrolling page. There are a bunch of Chrome extensions that do this, but to capture the Slack app, I recommend using CleanShot X on the Mac or SnagIt! on Windows.
Both of these allow you to select a window to be captured, let you scroll all the way down the windows, and then save that giant constructed graphic as a PNG, JPEG, or PDF.
This approach gives you a conversation that looks exactly like it looked when you were in Slack. Without OCR tools, you can't search or get to the underlying data, but it's a good evidentiary snapshot if you ever need to prove what was discussed with another party.
The key takeaway from this article is actually not the how-to advice I just gave. The key takeaway is to understand that Slack is not like email, and it doesn't automatically create an archive of your conversations. If your conversations are important to you, you'll need to be proactive in order to save them.
You might want to add archiving your Slack conversations to your normal workflow procedures on a regular schedule if documenting conversational history is important enough to you.