How does PDF SignCheck verify a PDF digital signature?

PDF SignCheck cryptographically validates the digital signatures embedded in PDF documents. It checks that the document has not been tampered with after signing, verifies the signer's certificate chain against trusted root Certificate Authorities (CAs), and outputs a stamped PDF with a "Verified ✓" badge — similar to clicking "Trust this certificate" in Adobe Acrobat.

Is my PDF document stored or saved during digital signature verification?

No. Your file is processed entirely in memory on the server. It is never written to disk, never stored in any database, and is discarded immediately after the verified PDF is returned to your browser. We take privacy seriously — your documents remain yours.

What types of PDF digital signatures and certificates are supported?

PDF SignCheck supports PDFs that contain PKCS#7 / CMS digital signatures — the standard used by government portals, official certificate authorities, and digital signing platforms. This includes documents from DigiLocker, e-District, MCA, UIDAI, and similar government services worldwide.

Why does Adobe Acrobat Reader display a PDF signature as "Not Verified"?

Adobe Acrobat only trusts certificates from its own Adobe Approved Trust List (AATL). Many government and institutional signers are not on that list. Our tool auto-trusts the signer's certificate after cryptographic verification — exactly what Adobe asks you to do manually when you click "Trust this certificate." The downloaded verified PDF includes a visual stamp so it's clear the signature has been validated.

Is the online PDF signature verification process cryptographically secure?

Yes. We perform full PKCS#7 signature verification: we extract the signed hash from the signature, independently compute the hash of the document's byte ranges, and compare them. We also validate the certificate chain up to a trusted root CA from the Mozilla CA trust store. This is the same process that Adobe Acrobat and other professional PDF tools use.

Are there daily or rate limits for PDF cryptographic verification?

To prevent abuse, we rate-limit to 10 requests per minute per IP address. The maximum file size is 50 MB. These limits are sufficient for normal usage. If you need higher throughput for enterprise use, please contact us.

Which Indian government certificates and portals are supported?

PDF SignCheck fully supports digital signature verification for official Indian government certificates. This includes UIDAI Aadhaar Cards, state e-District certificates (such as Caste, Income, Domicile, and Birth/Death certificates), DigiLocker-issued PDF documents, NFSA Ration Cards, Income Tax / PAN documents, and any official PDF signed via CCA India (Controller of Certifying Authorities) root credentials.

How do I resolve the "Signature Not Verified" or "Signature Not Checked" warning on Aadhaar or Caste certificates?

Simply upload your signed PDF to PDF SignCheck. Our system extracts the digital signature, cryptographically validates the hash integrity against trusted root certificates, and generates a stamped PDF. When you download this verified document, the signature will show as valid, making it suitable for direct submission.

How is the ink cost calculated?

Standard cartridges specify page yield at 5% coverage (ISO standards). We scan every pixel on each page of your PDF to measure Cyan, Magenta, Yellow, and Black coverage. We scale your custom cartridge costs and yields linearly relative to these percentages.

How does the browser scan pages?

Your document is loaded in-memory via PDF.js. Each page is rendered to an off-screen canvas in your browser. We then read the pixel buffer directly to calculate the CMYK values of every pixel. No files or data are uploaded to our servers for this scan.

What does the eco-friendly version do?

It applies server-side optimizations: Grayscale removes expensive color ink usage; Draft Mode lightens all colors by 25% (less toner density); and Remove Images completely strips graphical assets while preserving text and layout.

Are my files kept private?

Absolutely. The ink analysis is 100% client-side. The file is only sent to our server to generate the optimized eco-friendly version in-memory and is never saved or stored.

PDF Ink/Toner Cost Estimator

Estimate PDF Printing Costs

Upload any PDF, analyze exact CMYK ink/toner coverage per page, estimate printing cost based on your printer model, and download an optimized ink-saver version.

CMYK ScanPixel-Level Accuracy

InteractiveAdjust Specs Live

Eco SaverReduce Ink Up To 80%

Daily Limit

Upload your PDF

Drag and drop your file here, or click to browse

.pdf·up to 50 MB

100% Client-Side Scan

Files Never Saved

Eco-Friendly Save Mode

Zero-Knowledge Privacy

Files are processed strictly in secure memory modules inside your local browser. No server storage.

Cryptographic Standards

Fully compliant with IETF RFC 5652 (CMS), Adobe PDF specs, eIDAS, and Controller of Certifying Authorities (CCA).

Verify Anonymously

No personal registration or document tracking is required. Verify up to 2 files daily as guest.

Detailed Audit Trails

Generates downloadable, verified PDFs with structural signature stamps and trust summaries.

Edge Sandbox Security

Verification executes inside sandboxed browser modules to ensure isolated document handling.

Zero Data Logging

Absolutely no logging of files, names, email contents, or signature details. Pure privacy.

Process

How does the PDF ink and toner cost estimator work?

Estimate print cost and generate optimized version in four simple steps.

Upload Document

Drag and drop your PDF securely. Choose your printer class preset to preconfigure realistic average prices.

Pixel Scanning

Our browser worker renders each page thumbnail onto an off-screen canvas, analyzing RGBA colors to map actual Cyan, Magenta, Yellow, and Black coverage.

Adjust Live

Review page-by-page ink weight indicators, and adjust sliders for page yields, duplex sheets, or cartridge price settings to see real-time costs.

Optimize & Save

Apply Grayscale filter, draft ink-saver washes, or strip visual imagery entirely to construct a lighter PDF version, slashing print bills by up to 80%.

Features

How does advanced printing intelligence estimate page coverage?

Reduce toner waste and estimate exact costs before pressing print.

Privacy-First Scan

Analysis runs 100% in-browser. Your documents are scanned locally and never sent to our servers.

Interactive Recalculation

Adjust cartridge cost, pages yield, and copies. The estimator computes paper and ink costs instantly in real-time.

Ink-Saver Conversion

Select Grayscale, Lighten, or Image Stripping. Generate a cheaper print version to download free.

Zero Storage Policy

PDF optimization is processed entirely in-memory and immediately discarded. Nothing is ever stored in database or disk.

Support

Frequently Asked Questions

Everything you need to know about PDF print cost estimations.

How does the PDF Ink/Toner Cost Estimator work?

Our tool scans your PDF directly in your browser. Using PDF.js, we render each page onto an off-screen canvas, extract pixel data, and convert RGB colors to CMYK coverage percentages. We then apply standard print yields (which assume 5% coverage per channel) to calculate estimated cartridge consumption and paper cost.

Are my PDF files sent to a server for cost scanning?

No. The entire scan and analysis process runs 100% locally in your web browser. Your document is processed in-memory and never leaves your device during the estimation. Your privacy is fully preserved.

How is the cartridge page yield used in calculations?

Printer manufacturers rate cartridge yield at 5% page coverage. This means a 500-page cartridge can print 25 full "100% coverage equivalents". If you print a page with 10% coverage, it consumes twice the standard amount. Our calculator computes this on a page-by-page basis for exact precision.

What optimization options are available in the eco-friendly version?

We offer three modes: Grayscale Mode (converts color images and elements to shades of gray, saving expensive color toner), Draft Mode (reduces print density by washing out content by 25%), and Remove Images (completely strips graphics to leave only text and lines). You can combine these to save up to 80% on print cost.

What are the daily estimation and optimization limits?

Guests can perform up to 2 estimates/downloads per day. Free account holders get 5 per day, and Top-up Credits users get 100 per day. Limits are separate from other PDF tools on the site.

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Estimate PDF Printing Costs

Zero-Knowledge Privacy

Cryptographic Standards

Verify Anonymously

Detailed Audit Trails

Edge Sandbox Security

Zero Data Logging

How does the PDF ink and toner cost estimator work?

Upload Document

Pixel Scanning

Adjust Live

Optimize & Save

How does advanced printing intelligence estimate page coverage?

Privacy-First Scan

Interactive Recalculation

Ink-Saver Conversion

Zero Storage Policy

Frequently Asked Questions

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