Slack's file limit, and the free plan's history cap

People searching for Slack's storage limit are usually asking two different questions, and Slack answers them in two different help articles that never mention each other.

The first is how big a file can be. The answer is 1GB, on every plan, and it is almost never the problem.

The second is how much a free workspace can keep, and the answer has changed twice in three years. It is no longer measured in gigabytes at all.

The per-file limit: 1GB

Slack's help article on adding files states it in one line: "You can add files up to 1GB in size." There is no smaller figure for free workspaces and no larger one for paid plans. The limit page for Slack tracks that figure against the source.

A gigabyte is large enough that an ordinary screenshot, PDF or screen recording never approaches it. A full-length 4K phone video might, at roughly 350–750MB per minute at the highest settings, and a two-minute 4K/60 clip can clear the limit. That is the one file type that genuinely hits it.

The free plan's limit: 90 days, not gigabytes

Older descriptions of the free plan quote a 5GB total storage cap. That is out of date. Slack's current usage-limits article for the free version says:

• "You can view and search messages and files from the last 90 days."
• When the workspace reaches that, "Slack will start hiding messages and files older than 90 days to make room for new ones."
• Workspace owners can choose to "keep all messages and files for one year, or delete them after 90 days."
• "Starting 26th August 2024, Customer Data, such as messages and file history, older than one year may be deleted on a rolling basis from workspaces on the free subscription."

So the free plan's ceiling is time. Files do not stop uploading because the workspace is full; they stop being visible because they are old. And since August 2024, old is not just hidden: after a year it may be gone.

That changes what "running out of space" means. Compressing files does nothing for a 90-day window. What it does affect is the second cap people hit, which is the one on the other side of the upload.

Where compression does matter on Slack

Downloads on a phone. A 40MB screen recording in a channel is downloaded by every person who taps it. Twelve people on mobile data is half a gigabyte of someone else's allowance for a clip that would have been fine at 8MB.

Previews. Slack generates inline previews for images and short videos, and a 14-megapixel retina screenshot takes a noticeable moment to render in a thread where a 1,600-pixel one is instant. Why a screenshot is that big, and the lossless ways to shrink one is the usual fix.

The export. When a free workspace reaches its year and the owner exports before it is deleted, the export is every file ever uploaded. A channel of uncompressed screen recordings becomes tens of gigabytes to download and store.

Forwarding to somewhere with a real limit. Slack is often the first hop. The file that sat happily in a channel at 60MB then has to go to a Teams chat with a 100MB cap, a Notion page on the free plan at 5MB, or an email where the practical ceiling is 18MB. Compressing once, to the smallest limit it will ever meet, saves doing it later.

Sensible sizes for the three things people post

What	Typical as uploaded	Sensible	How
Full-screen retina screenshot	3–8MB PNG	300–500KB	Crop, halve the dimensions, lossless WebP
1-minute screen recording, 1440p	60–150MB	10–20MB	Re-encode at 2 Mbps, 1080p
Scanned or exported PDF, 10 pages	5–15MB	under 1MB	Lossless rewrite, then image resolution

None of those is a Slack rule. They are the sizes at which the file loads instantly for the reader and costs nothing to forward, which is what matters once the 1GB cap is not the constraint.

Compress an image to 500KB, a video to 50MB or a PDF to 1MB does each one in the browser, measures the real output and keeps it under the number, with nothing uploaded anywhere but Slack. For a screenshot of an internal dashboard or a recording of a customer call, the "nothing uploaded" part is not a detail.

The numbers Slack publishes, in one place

Limit	Figure	Applies to
Single file upload	1GB	Every plan
Message and file visibility, free plan	Last 90 days	Free
Retention option, free plan	Keep one year, or delete after 90 days	Free, owner's choice
Deletion of data over one year, free plan	May be deleted on a rolling basis, from 26 August 2024	Free
Total file storage	No published cap	All plans

Both source articles are linked from the Slack entry on the limits page, with the date they were last checked.

FAQ

What is the maximum file size on Slack?

1GB per file, on every plan, including the free one. Slack's help article on adding files states it directly. It is large enough that screenshots, documents and most videos never reach it; only a long 4K phone recording is likely to, and re-encoding that to 1080p is the fix.

Does the Slack free plan have a storage limit?

Not in gigabytes any more. The free plan limits history: messages and files from the last 90 days are visible, older ones are hidden, and since 26 August 2024 data older than one year may be deleted from free workspaces on a rolling basis. Workspace owners can choose between keeping a year or deleting after 90 days. Compressing files does not extend the window.

Why should I compress files for Slack if the limit is 1GB?

Because the limit is not the cost. Every person who opens a file downloads it, previews render slower for large images, a year's export becomes enormous, and files posted in Slack are usually forwarded on to somewhere with a real cap, such as email, Teams chat or Notion. Posting a 500KB screenshot instead of a 6MB one costs nothing and saves all of that.

Is Slack's file limit different for free and paid plans?

No. The 1GB per-file figure applies to all plans. The differences between plans are history (90 days visible on free, unlimited on paid), app integrations and administration features, not upload size.