Understanding file size and format limits
2 min read
Updated Apr 11, 2026
Most upload issues are easy to prevent. The current workflow expects PDF as the signable input and enforces a size ceiling so preparation stays predictable.
Before you begin
A source file ready for upload
Awareness of the file size
A way to convert non-PDF source documents if needed
Use PDF for signing
PDF is the canonical signable format in the current Signelio workflow.
If your source file is in another format, convert it before upload rather than assuming the app will transform it automatically.
Respect the size ceiling
The upload step currently supports PDF files up to 20 MB.
If a file is too large, reduce it before you start the draft so preparation and preview remain manageable.
Plan for readability, not just acceptance
A technically valid file can still be a poor signing experience if pages are cluttered or low quality.
Optimize for legibility, especially if recipients often sign from mobile browsers.
Pro Tips
Compress oversized PDFs before upload instead of splitting the workflow into several packages without a plan.
Check every page after conversion from another format.
Keep source assets versioned internally so you know which PDF was uploaded.
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