Trusted By India's Biggest Brands
Why Businesses Trust Our Digital Signature Platform
A comprehensive solution designed to give you ironclad legal protection with IT Act-compliant digital signing.
Flexible Certificate Support
Compatible with all USB tokens, Class 2 & 3 DSC from any licensed Certifying Authority in India.
Multi-Signature Capability
Enable multiple authorized signatories to sign the same document with their individual certificates.
Bulk PDF Signing
Sign hundreds of documents in a single batch operation, saving valuable time and effort.
Legally Binding & Compliant
Fully compliant with IT Act 2000 & Indian Evidence Act, ensuring your signatures hold legal validity.
Time Stamping & Integrity
Cryptographically secure timestamps and tamper-evident seals ensure document integrity and non-repudiation.
Offline Desktop App
Enhanced security with a fully offline desktop application that never uploads your sensitive documents to any server.
Long-Term Validation (LTV)
Signatures remain valid even after certificate expiry with secure timestamps and tamper-proofing.
Custom Signature Appearance
Choose where your signature appears, first page, last, all pages; customize look and metadata as needed.
Advanced Security
Secured signing with SHA-256, 384, 512 algo, RSA 2048-bit encryption, along with PAdES ETSI EN 319 142-1 compliance.
The Fastest Way to Sign PDFs Securely
Four simple steps to legally sign your PDF documents
Select your PDFs
Select single or multiple PDF files from your computer
Connect USB DSC token
Insert your USB token and enter your PIN when prompted
Configure signature options
Choose signature position, appearance, and other settings
Sign and save
Complete the signing process and save your signed documents
Benefits of Digital Signatures
Transform your document workflows with legally valid digital signatures that save time, money, and resources.
Faster turnaround times
Sign documents in seconds instead of days. No more printing, physical signing, scanning, and courier delays.
Reduced paperwork and cost savings
Eliminate printing, storage, and courier costs. Save on paper, ink, filing cabinets, and physical storage space.
Enhanced security and trust
Cryptographic signatures provide tamper-evidence, non-repudiation, and verification of signer identity.
Eco-friendly & paperless workflows
Reduce your carbon footprint by eliminating paper usage and associated transportation emissions.
Legal enforceability
Digital signatures are legally recognized under Indian IT Act, 2000 and Indian Evidence Act, providing the same legal status as handwritten signatures.
Legal Validity & Compliance
Our digital signature solution is fully compliant with Indian regulations, ensuring your signed documents are legally valid and enforceable.
- Compliant with IT Act, 2000 recognizing digital signatures as legally valid
- Adheres to Indian Evidence Act provisions for electronic records
- Supports certificates issued by licensed Certifying Authorities in India
- Implements PKI standards for cryptographic security
- Maintains audit trails and timestamp verification
Use Cases Snapshot
Digitally sign critical documents - faster, safer, and fully compliant.
Legal Documents
Sign legal agreements, contracts, NDAs, and licensing documents with full compliance.
HR Documents
Quickly sign and issue appointment letters, onboarding docs, and salary slips.
Sales & Vendor Docs
Digitally sign sales contracts, agreements, distributor documents, and more for vendor relationship.
Intellectual Property
Securely sign IP licensing, confidentiality, and legal documents for IP protection.
Finance & Accounts
Sign invoices, POs, balance sheets, and MIS reports without printing a single page.
Tenders & Bids
Easily sign government tenders, bid submissions, and procurement forms digitally.
Educational Institutions
Sign student records, certificates, admission letters, and affiliation documents.
Healthcare & Pharma
Sign prescriptions, lab reports, compliance declarations, and patient consent forms.
Helping Our Customers Succeed
See How 1.5 Lakh+ Users Are simplifying Their Document Signing With Us
CA. Rajiv Bansal (Financial Advisor) 
Their Support centre is Simply Amazing They Solve Your Problems in a Minute. I have some technical Issue Their Representative Vishal Bansal Solve my issues within a very short time.
Gopal Agarwalla
"I Had Great Experience From Miss Khushboo Agarwal For Issue Related To KDK Tds Excel Export. She Had A Very Good Knowledge And A Very Kind Tone. That's Excellent Issue Resolve In Just Few Minutes. 5 Star For Support."
Vishal Bansal
"Thank You So Much Really Fast Response From KDK Software Team Especially Vishal Sir Response Great Within Limited Time Period He Did Wonderful Task And Resolve My Problem Thank You Sir And Thank You KDK Software Team"
Saloni Jain
"1 Cloud Base Is Good 2 Can Used From Anywhere 3 Single Click GSTR1/ 3B Downloads. 4 2B Reco. 5. Auto 2B Email To Clients And Email Feature To Some More Points Demo Given By Your Person With Good Explanation And Example Live"
Khileshwar Sahu
"Awesome Support System. They Will Resolve Your Queries From All Perspectives. Some Of The Support Staff Are Very Cooperative. I Have Talked With Shyam. He Is Such A Nice And Kind Person. Thanks And All The Very Best"
Dhaval Pandya
"Nice Software Using For Last More Than 10yrs Since I Was Doing Articleship. Its Presentation Style Is Very Good In Compare To All Other Softwares In Market I Highly Recommend The Same."
Priya Sharma
Excellent digital signing tool. The bulk signing feature has saved us hours every month when processing salary slips for our 500+ employees.
Rajesh Kumar
Very easy to use and legally compliant. Our legal team relies on Zen PDF Signer for all NDA and contract signings. Highly recommended!
Anita Mehta
The offline functionality is a great security feature. We handle sensitive financial documents and knowing they never leave our network gives us peace of mind.
Suresh Patel
Switched from manual signing to Zen PDF Signer and our document turnaround time dropped from 3 days to 3 minutes. Outstanding product!
Kavita Nair
As a CA firm, compliance is everything. Zen PDF Signer gives us full IT Act 2000 compliance with a straightforward interface.
Mohan Verma
The DSC token integration works flawlessly. We've processed thousands of documents without a single authentication failure.
Deepa Krishnan
Setup was quick and the support team was extremely helpful. Within 30 minutes we were signing documents digitally.
Amit Joshi
Long-Term Validation support means our archived documents remain valid years after signing. Critical for our audit trail requirements.
Sunita Agarwal
The custom signature appearance feature lets us brand our signed documents professionally. Our clients are always impressed.
Vikram Singh
Handles our bulk tender document signing with ease. Used to take our team half a day; now it's done in under an hour.
Rekha Sharma
Finally a PDF signing tool that understands Indian compliance needs. Class 3 DSC support and PKI standards all in one package.
Naveen Gupta
We use Zen PDF Signer for all our vendor agreements. The multi-signature capability has streamlined our approval workflows significantly.
Pooja Reddy
Paperless HR is now a reality for us. Appointment letters, offer letters, salary slips — all digitally signed and delivered instantly.
Sanjay Malhotra
SHA-256 encryption and RSA 2048-bit security meets our pharmaceutical regulatory requirements. Compliance team approved.
Asha Rao
The time-stamping feature is invaluable for our legal department. Non-repudiation is guaranteed on every signed document.
Rajan Tiwari
Customer support is phenomenal. Any queries are resolved promptly and the team really understands the product inside-out.
Meena Iyer
As an educational institution we sign hundreds of certificates annually. Bulk signing has transformed our certificate issuance process.
Sunil Desai
Excellent value for money. The features offered at this price point are unmatched in the Indian digital signing market.
Nisha Kapoor
The interface is clean and intuitive. Even non-technical staff in our HR department can sign documents without any training.
Got Questions? We've Filed the Answers.
From multi-client handling to data security—here's everything you need to know before you switch to a smarter signing solution.