Does Slack Remove EXIF Metadata? The Gap Between Promise and Reality

The 2020 Announcement — and What Testers Found

In May 2020, Slack quietly confirmed something significant: the platform had begun stripping EXIF metadata — including GPS coordinates — from images uploaded to workspaces. TechCrunch reported the change after testing it directly, uploading a geotagged photo and confirming the downloaded copy no longer carried location data. The news spread quickly across the privacy community. Problem solved, right?

Not quite. Within days, security researchers started poking holes in that narrative. Motherboard (Vice) verified that Slack preserved image metadata when using the service's web client. Security analyst Jerry Gamblin highlighted the inconsistency publicly. Ryan O'Horo, a security consultant who built slack-metabot — a tool specifically designed to extract EXIF data from files uploaded to Slack channels — confirmed that metadata was still being extracted from Slack-hosted images in his testing environment. The stripping Slack announced wasn't happening uniformly across all upload paths and file types.

What Slack Actually Strips — and What It Keeps

Here's where it gets nuanced. Slack's stripping behavior is not binary — it doesn't simply strip everything or nothing. Based on documented testing and researcher findings, the picture looks more like this:

The 2020 TechCrunch test specifically used JPEG images through what appeared to be the desktop or mobile app path. That specific combination — JPEG, official app — showed GPS removal. Change either variable, and the results diverge. Upload a PNG. Use the web browser client. Share through a third-party Slack integration. Any of these paths may bypass whatever stripping pipeline Slack built.

Why File Type Changes Everything

EXIF data lives in JPEG and TIFF files by specification. PNG uses a different metadata system called XMP — Extensible Metadata Platform — stored as text chunks within the file. RAW files from cameras carry proprietary manufacturer-specific metadata. Each format requires a different stripping approach.

Slack's 2020 update appeared focused on EXIF in JPEG files — the most common format for smartphone photos shared in consumer contexts. But workplaces deal with a wider range of file types. Screenshots saved as PNG. Photos from certain Android apps that default to PNG. Design assets with embedded XMP describing creation tools, author names, and organizational metadata. The broader social media metadata comparison shows this is a consistent gap across platforms: most stripping policies were written with JPEG in mind and leave other formats under-addressed.

For journalists and activists, this isn't theoretical. The Vice article that documented Slack's metadata survival specifically raised the scenario of a journalist exchanging photos with an editor via Slack. Even if the journalist manually strips metadata before publishing, the original file with intact metadata sits in the Slack channel — accessible through legal discovery, admin export, or a future data breach. That retained copy becomes a liability the journalist may not even know exists.

Channels vs. Direct Messages: Does It Matter?

Intuitively, you might expect DMs to receive stronger privacy protection than public channels. In practice, there's no documented evidence that Slack applies different stripping behavior to files shared in DMs compared to channel uploads. Both pathways appear to be subject to the same inconsistent pipeline.

What does differ is who can access those files. Channel files are visible to all channel members. DM files are visible only to the conversation participants. But workspace admins on Business+ and Enterprise Grid plans can export DM content — including files — under Slack's data export policies. So if your goal is keeping metadata away from everyone except your intended recipient, DMs don't meaningfully improve your situation. The file still lives on Slack's servers with whatever metadata survived upload.

This is similar to the pattern documented in Microsoft Teams' metadata handling, where DM file sharing also failed to provide meaningfully stronger metadata protection than channel uploads. B2B collaboration tools tend to prioritize data retention and discoverability for compliance reasons — the opposite of aggressive privacy stripping.

The B2B Exposure Problem No One Talks About

Most metadata privacy coverage focuses on consumer social platforms — Instagram, X, TikTok. Slack barely registers in the public conversation, despite being where millions of people share photos every day in a professional context. And workplace photo sharing carries distinct risks that consumer sharing doesn't.

Think about what employees routinely share in Slack channels: photos of client sites taken on personal phones, pictures of equipment for IT support tickets, screenshots of sensitive documents, images from company events that reveal attendee locations. In consumer social media, you control who follows you. In a Slack workspace, you may be sharing with hundreds of colleagues in a company-wide channel — and you probably haven't thought once about whether that photo of the conference room reveals your office's GPS coordinates.

Workspace admins present another dimension. Even on teams where the admin is trustworthy, admin-level Slack credentials represent a high-value target. If a workspace is compromised, the attacker gains access to every file ever shared — including files with metadata that was never stripped. For organizations handling sensitive work — law firms, healthcare companies, investigative newsrooms — this is a genuine risk surface that Slack's partial stripping does nothing to eliminate.

Before uploading anything sensitive to a shared channel, stripping metadata manually is the reliable path. You can do that with command-line tools like ExifTool, or if you want a faster workflow, MetaClean's image tool processes files directly in your browser — nothing gets uploaded to any server — and cleans all EXIF fields in seconds. That way, whatever Slack's pipeline does or doesn't do is irrelevant to your privacy.

What Slack Retains on Its Servers

There's a distinction that matters here, similar to what we documented in LinkedIn's metadata handling: there's a difference between what metadata is stripped for display purposes versus what Slack retains in its data infrastructure.

Slack's own privacy policy confirms that the platform stores files shared in workspaces, and that workspace owners and administrators control data retention. Under Business+ and Enterprise Grid plans, all files — including originals — can be exported. What this means practically: even if Slack strips GPS from the version of your photo that other users can download, Slack may retain the original uploaded file internally with metadata intact.

This parallels X/Twitter's behavior, where the Data Download archive preserves original uploaded files that contain metadata stripped from public-facing versions. The distinction between what public users see and what the platform retains is crucial for anyone whose threat model includes platform-level data access rather than just peer-to-peer privacy.

Who Is Actually at Risk

Not everyone sharing photos in Slack faces the same exposure. The risk profile varies significantly by use case.

Journalists and activists face the highest-stakes risk. Sharing source photos via Slack — even in private DMs — creates a metadata-bearing copy that can be legally compelled or obtained through a breach. The Vice article called this out explicitly as a concern for these communities.

Remote teams photographing client sites may inadvertently share precise GPS coordinates of client locations with every channel member. A field technician who photographs a building issue and posts it to a project channel has just broadcast the building's exact coordinates to everyone subscribed.

Employees working from home who photograph documents or equipment at their home office and share in Slack may expose their home address via GPS metadata — to colleagues, admins, and potentially anyone who gains access to the workspace.

HR and legal teams sharing document scans or photos of physical files in Slack channels may not realize that metadata from scanning software, author information from office applications, or GPS data from mobile photos can survive in those files.

Compare this with platforms covered in our WhatsApp metadata analysis — WhatsApp actually strips EXIF quite aggressively from images sent through its compression pipeline. The irony is that the consumer messaging app provides more reliable metadata protection than the enterprise collaboration platform that explicitly announced stripping it.

Your Protection Strategy

Given the inconsistency, relying on Slack to clean your photos isn't a strategy. The only reliable approach is pre-upload stripping — removing metadata before the file ever reaches Slack's servers.

For individual users: build the habit of checking images before sharing in any professional context. ExifTool is free and powerful for technical users. For a no-install option that processes files entirely in your browser, MetaClean's EXIF remover handles batch cleaning with no uploads required — your files never leave your device. That property matters for workplaces where sensitive files shouldn't be uploaded to additional third-party services even for cleaning.

For teams: the right fix is policy, not trust. Establish a standard that sensitive photos get stripped before entering any collaboration tool — Slack, Teams, Google Chat, or anything else. A one-time workflow change protects against every platform's inconsistencies simultaneously.

Frequently Asked Questions

Does Slack remove GPS location from photos?

Sometimes. Slack announced GPS stripping for uploaded images in May 2020, and it works for JPEG uploads through the official desktop and mobile apps in many cases. However, security researchers have documented GPS data surviving through the web browser client and in certain file types like PNG. There's no guarantee stripping occurs on every upload path, making pre-upload removal the only reliable approach.

Can other Slack workspace members see my photo's metadata?

Yes, if the metadata survives Slack's processing pipeline. When someone downloads an image from a Slack channel or DM, they receive the file as stored by Slack — which may include GPS coordinates, device model, and capture timestamps if those fields weren't stripped during upload. Anyone with channel access can download and inspect the file.

Does Slack strip EXIF from PNG files?

Based on documented research, PNG files are more likely to retain metadata through Slack than JPEG files. PNG uses XMP metadata rather than EXIF, and Slack's stripping pipeline appears to have been built primarily with JPEG in mind. The slack-image-metadata-poc project specifically demonstrated XMP metadata surviving intact in PNG files served through Slack.

Can Slack admins access metadata in uploaded photos?

Workspace admins on Business+ and Enterprise Grid plans can export workspace data including files. The exported files are the originals as uploaded, which may contain full metadata regardless of what stripping occurred during display. If your organization retains data exports, any metadata in uploaded photos is accessible to admins with export permissions.

Is sharing photos in Slack DMs safer than in channels?

For metadata specifically, there's no documented evidence that Slack applies stronger stripping to DM uploads versus channel uploads. The same inconsistencies apply in both contexts. DMs limit who can see the files within Slack's interface, but workspace admins can still access DM files on plans that allow data export.

What's the safest way to share photos in Slack without exposing metadata?

Strip EXIF data from photos before uploading them to Slack — this eliminates any dependency on Slack's processing behavior. ExifTool works for technical users, while browser-based tools like MetaClean process files locally without uploading them to additional servers. This approach protects privacy regardless of whether Slack's stripping pipeline catches the file.