Toolzo Blog
Free guides on exam photo & signature sizes, compressing images and PDFs, and converting documents — written and reviewed by the Toolzo team.
Reduce photo KB without losing quality
Why phone photos are so much bigger than what forms accept, what actually causes visible quality loss during compression, and how to get the smallest file that still looks sharp.
Photo size terms explained: DPI, pixels, cm
A plain-language explanation of DPI, pixels, cm, mm, KB and file format — the terms every exam form's photo specification uses, and how they relate to each other.
JPG vs PNG vs WebP: which to use
A practical comparison of JPG, PNG and WebP for Indian exam forms, websites and everyday photos — when each format actually makes sense.
How to send a photo as PDF on WhatsApp
How to turn a photo into a PDF before sending it on WhatsApp, and why that avoids the quality loss WhatsApp applies to images sent directly.
Signature size for exam forms (10KB–20KB)
Why exam form signature uploads have such a tight 10-20KB limit, how to photograph a signature that survives compression, and the size table across major Indian exams.
How to save a Word file as PDF
How to convert a Word document to PDF without Microsoft Word installed, including the Hindi-font issue that breaks a plain print-to-PDF export.
RRB, NDA, IBPS & Bank PO photo–signature size
Photo and signature size for RRB (Railway), NDA and IBPS/Bank PO exam forms in one reference list, with the caveat on which figures can change per notification.
How to resize a photo to 20KB without losing quality
How to get a photo under 20KB while keeping it as sharp as possible, focusing on the source-photo choices that matter more than the compression tool itself.
UPSC photo and signature size — full guide
UPSC application photo and signature size explained — 200×230px photo, 140×60px signature, KB limits and JPEG format — plus what changes between UPSC exams.
How to reduce image size on mobile
How to shrink a phone photo to an exact KB target directly on Android or iPhone, without a computer, and why phone photos are so much larger than what most forms accept.
SSC CGL & CHSL photo and signature size
SSC exam form photo and signature size — 200×240px photo, 160×60px signature — with the exact KB ranges SSC's One-Time Registration (OTR) system checks.
Make a black & white or mirror image photo
How to convert a photo to black and white or flip it into a mirror image, with the real reasons each edit is needed for ID forms, printing or fixing a backwards photo.
Passport size photo dimensions explained
Indian passport photo dimensions — 35×45mm, white background, JPEG under 300KB — explained with the difference from a generic 'passport size' photo used on other forms.
How to extract text from an image
How to pull editable text out of a photo, screenshot or scanned notice in Hindi or English, and what makes OCR accuracy better or worse on a given image.
PAN card photo and signature size
NSDL/UTIITSL PAN application photo and signature size — 3.5×4.5cm photo, exact KB range — plus common upload errors and how to fix them free.
How to convert PNG to JPG
How to convert PNG or iPhone HEIC photos to JPG for forms and portals that reject them, and what actually happens to quality and transparency during the conversion.
Aadhaar card size in cm, inches and pixels
Aadhaar card and Aadhaar photo dimensions explained in cm, inches, mm and pixels at 300 DPI, with a quick converter reference table.
How to convert PDF to Word
How to turn a PDF into an editable Word document, why some PDFs convert perfectly and others need OCR first, and what to check in the output before you rely on it.
Aadhaar photo size and how to make it
The exact Aadhaar enrolment/update photo specification — 600×600px, 20-100KB, white background — plus common rejection reasons and how to make one free.
How to convert JPG to PDF under 100KB
How to combine one or more JPG photos into a single PDF that stays under 100KB, and why compressing the images before assembly beats compressing the finished PDF.
How to compress a PDF to 400KB
How to shrink a PDF to under 400KB without losing pages or making text blurry, and why scanned PDFs compress very differently from text-only ones.
How to compress a photo to 50KB
How to compress a photo to exactly 50KB or 100KB for exam and document uploads, and why these two targets behave differently from a tighter 20KB limit.
How to compress an image to 20KB
Step-by-step way to compress a photo to exactly under 20KB for exam forms, with why 20KB is so hard to hit manually and what actually controls the final size.