PDF Too Large for Slack? Fix 1GB Limit Instantly

Getting a file too large error uploading a PDF to Slack? Compress your PDF below 1GB instantly using the tool below — or below 10MB for Slack API integrations.

⚡ Slack File Size Limits (Quick Fix)

•Slack allows file uploads up to 1GB per file for all users.
•For API-driven or user-facing file inputs in Slack integrations, the effective limit is 10MB per file.
•Free Slack workspaces have 5GB total storage per workspace with 90-day file retention.

👉 Fix: Compress your file below 1024 MB using the tool above.

📄

Drop your PDF here

or click to upload — PDF only

Target size (optional)

targeting 1024 MB

How to use this tool

Select or drag and drop your file into the tool above.
Adjust the settings or target size as needed for your specific requirement.
Wait a moment while your file is processed directly in your browser.
Download the final file safely to your device.

About this tool

Slack's 1GB limit is rarely hit by standard PDFs — the more common cause is a Slack API integration enforcing the 10MB limit. Identify which limit applies to your situation and compress accordingly.

Email attachment rejected? Reduce your PDF file size below 20MB instantly — works for Gmail, Outlook, and Yahoo.

Compress PDF for Slack

Reduce your PDF to under 1GB for Slack file uploads — or under 10MB for API-driven integrations.

Slack File Upload Failed? Fix PDF Size Error Now

Slack upload failing? Fix PDF file size errors for both standard uploads and API integrations instantly.

💡 Good to know

→Slack allows file uploads up to 1GB per file for all users.Slack Help ↗
→For API-driven or user-facing file inputs in Slack integrations, the effective limit is 10MB per file.Slack Help ↗
→Free Slack workspaces have 5GB total storage per workspace with 90-day file retention.Slack Help ↗

❓ Frequently Asked Questions

Why is my PDF too large for Slack?+

Standard Slack uploads allow up to 1GB per file — very few PDFs exceed this. If you're hitting a size error, you're likely using a Slack API integration with a 10MB limit. Compress below 10MB and retry.Source: Slack Help ↗

What is the Slack file size limit?+

1GB per file for standard uploads. 10MB for API-driven and user-facing file inputs in Slack integrations.Source: Slack Help ↗

How do I fix a Slack file too large error?+

Compress your PDF using the tool above. If you're uploading via the Slack UI, compress below 1GB. If you're using the Slack API or a bot integration, compress below 10MB.Source: Slack Help ↗

Can I send a 500MB PDF on Slack?+

Yes. Standard Slack uploads support files up to 1GB, so a 500MB PDF will upload without issues via the Slack UI.Source: Slack Help ↗

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