BiGapiguides
POST /v1/pdf/compare · 1 cent per page

Compare PDFs

Visually compare two PDFs page by page: change percentage per page as JSON, or a diff PDF with changes highlighted in red. Billed per page.

Try it

curl -X POST https://api.bigapi.dev/v1/pdf/compare -H 'Authorization: Bearer $KEY' -F 'file=@v1.pdf' -F 'file=@v2.pdf'

New keys come with 100 free operations, no signup: curl -X POST https://api.bigapi.dev/v1/keys. Failed calls cost nothing.

Parameters

NameMeaning
file requiredTwo PDF files (field name "file", twice).
dpiResolution for the page-by-page comparison, 50 to 200. Raise it to catch very small changes; higher is slower.
Default: 100
thresholdHow different a pixel must be to count as a change, 0 to 64 per colour channel. Raise it when scan noise or font smoothing shows up as changes.
Default: 12
outputjson returns a report of changed pages, pdf returns an overlay PDF with changes marked in red.
Allowed: json, pdf
Default: "json"

Result and price

1¢/p · 1 cent per page

Returns application/json | application/pdf. Response headers carry the cost (X-BigAPI-Cost) and notes about your input (X-BigAPI-Warnings).

From an agent (MCP)

Connect BiGapi as an MCP server: https://api.bigapi.dev/mcp (hosted) or npx -y @bigapi/mcp (local). Then ask in plain words; the agent finds pdf_compare on its own.