TECHSA KNOWLEDGE BASE · UPDATED AUGUST 14, 2026
Practical guides for everyday online tools
These original guides explain the preparation, checks and limitations behind common tool tasks. They are written for people using a phone or computer to submit documents, share information or verify a quick calculation—not just for people looking for a download button.
Document and image guides
Merge PDF files safely
Order job, college and application documents, then inspect the final PDF.
Make a PDF from images
Prepare readable phone scans, receipts and photographed pages.
PDFs for job applications
A detailed India-focused checklist for resumes and supporting documents.
Choose private PDF tools
Understand local processing, CDNs and sensible document handling.
QR codes and calculators
Create reliable QR codes
Make scannable QR codes and test them before printing or sharing.
UPI QR safety guide
Know what a payment QR can do and how to share it safely.
Use calculators responsibly
Understand estimates, rounding and when an independent check matters.
GST calculation guide
Check inclusive and exclusive GST calculations before using an invoice.
More reading
Our article library collects practical topics and links each topic back to the relevant tool. For help with a particular page, visit Help or contact techSA.