Slack Investigations Simplified: Best Practices, Tools, & Tactics from the Industry Experts

Slack has transformed internal communication and with it, the landscape of eDiscovery.

What used to be a fairly linear process of collecting emails and documents has evolved into navigating fragmented, fast-moving chat data across sprawling channels and DMs.

Recently, Reveal hosted a conversation with Janessa Nelson, Director of Legal Operations at Attentive, and Jeremy Robertson, Discovery Manager at Peloton, who shared how their teams are adapting to the challenges of Slack-based investigations, the solutions they’ve implemented, and why traditional methods no longer suffice.

Slack ≠ Email: Stop Treating It That Way

Slack is fundamentally different from traditional evidentiary sources. Unlike email or formal documents, Slack is dynamic, non-linear, often not following a predictable way of communicating. Conversations unfold in real time, with threads that fork unpredictably, and messages that can be edited, deleted, or lost entirely if not properly preserved. Default retention settings may be far shorter than what legal obligations require.

What’s more, Slack tends to capture a different tone than email. People often think less before sending a direct message or posting in a channel, and they may assume “no one’s really reading.” As a result, Slack can surface unvarnished, off-the-cuff thoughts—making it both more valuable and potentially more damaging in discovery, depending on the circumstances of the matter.

“Treating Slack data like email is a recipe for missing critical evidence or over-collecting irrelevant content,” Nelson says. It’s a mistake to assume Slack data is just "chat-flavored email." It requires its own discovery strategy, one that accounts for:

• Version history and message edits

• Deleted content and ephemeral messaging

• Complex channel architecture and permissions

• Volume and velocity of messages

Trying to shoehorn Slack into traditional workflows leads to inefficiencies, blind spots, and, most critically, defensibility risks.

Smart Search Is Key to Speed and Sanity

Smart search is key to saving time and reducing overwhelm when investigating Slack messages. Without a focused approach, searching can quickly become overwhelming due to the massive volume of data. That’s why it’s important to narrow searches early on by focusing on specific people, channels, and timeframes, this helps teams find relevant information faster. Using targeted keywords combined with logical operators allows searches to pinpoint related phrases or terms, making results much more accurate. Additionally, examining message details such as edits or deletions provides crucial context that might reveal attempts to hide or change information.

This approach matters because it cuts down on unnecessary data collection, reduces exposure to irrelevant or sensitive content, and significantly speeds up response times. When done effectively, legal and compliance teams can answer urgent questions in minutes instead of days, improving efficiency, protecting privacy, and minimizing risk.

Avoid the PDF Trap: Be Precise with Exports

Unfortunately, it’s not uncommon practice to export an entire Slack channel to PDF, then redact all but a few messages. Not only is that wildly inefficient, but it also increases risk and invites unnecessary scrutiny.

Instead, legal teams should aim for message-level exports with flexible options:

• Export only the relevant messages, with surrounding context

• Choose between native, HTML, or PDF formats

• Include metadata like timestamps, authorship, and edit history

This level of precision is key for responding to investigations, meeting production deadlines, and minimizing downstream review costs.

Use Technology that Understands Slack

While process is crucial, having the right tools makes all the difference. Platforms like Reveal Onna provide powerful Slack connectors designed specifically for eDiscovery, enabling teams to collect, search, and export Slack data efficiently while preserving metadata and maintaining defensibility.

“Technology is only as good as the process behind it,” Robertson explained. “Tools like Onna have been a game changer for us. They help bridge the gap by making Slack data accessible and manageable.”

Choosing a platform that understands Slack’s unique structure helps avoid common pitfalls and streamlines discovery workflows.

Control Costs before Clock Starts Ticking

A major takeaway: You’ll spend far less money and avoid major delays if you prepare before litigation hits. Here’s a sneak peek from the webinar of what our panelists had to say:

Being proactive reduces friction when matters arise and delivers a better ROI on your eDiscovery program.

Final Thoughts: Slack Isn’t the Problem, Lack of Process Is

Slack is here to stay, and it’s increasingly central to the way organizations communicate. The risk lies not in using Slack, but in failing to adapt legal and discovery processes accordingly.

If your teams use Slack for daily work, your discovery approach must reflect that reality. That means modern tools, updated policies, and well-documented workflows, all geared toward preserving, collecting, and producing chat data efficiently and defensibly. Watch on-demand webinar