PDF Basics
What Is a PDF File? How PDFs Work and Why Everyone Uses Them
What is a PDF file? What PDF stands for, what's inside one, digital vs scanned PDFs, forms, PDF/A and passwords, and how to open, create and edit PDFs.
Guides to PDFs, Photos and Everyday Maths
Step-by-step answers for PDFs, photos and everyday maths, with examples you can check.
Featured guides
Merge, Split & Organize
How to Merge PDF Files on Any Device (Free, No Software)
How to merge PDF files in a browser, on a Mac, Windows PC or phone, and get the page order, page picking, rotation and bookmarks right before you save.
Compress & Optimize
How to Compress a PDF to 1MB or Less (Resumes, Reports, Forms)
Compress a PDF to 1 MB without blurry text: shrink the photos at the source, pick the gentlest setting that works, then test the links before sending.
Latest guides
Edit, Sign & Secure
Aadhaar Card PDF Password: Format, Examples and How to Remove It
The Aadhaar card PDF password is the first four letters of your name in capitals plus your birth year. See UIDAI's examples, common mistakes and fixes.
Finance Calculators
CAGR Formula With Examples: How to Calculate Growth Rate
The CAGR formula with three worked examples, tested Excel formulas (RRI and the power method), the mistakes that skew the result, and when to use XIRR.
Finance Calculators
Compound Interest Formula With Examples (Yearly, Quarterly, Monthly)
The compound interest formula worked on ₹1 lakh with yearly, quarterly and monthly compounding, plus simple vs compound interest and the effective rate.
Compress & Optimize
How to Compress a PDF to 100KB (or Any Size Limit) for Online Forms
Get a PDF under 100 KB, or any upload limit, in minutes: the right compression settings, what to do when it won't shrink, and how to keep text readable.
Compress & Optimize
How to Compress a PDF to 200KB, Even a Multi-Page Scan
Compress a PDF to 200 KB even when it holds several scanned certificates: work out a per-page budget, merge before compressing, and keep stamps legible.
Convert to & from PDF
How to Convert a Bank Statement PDF to Excel (Clean Rows, Real Numbers)
Convert a bank statement PDF to Excel with one row per transaction and amounts you can add up, then prove nothing went missing with a balance check.
PDF Not Opening? Fixes for Windows, Mac, Android and iPhone
PDF not opening? Find the cause from the symptom: a damaged download, a password, a blank page in Chrome or the wrong app, then repair a corrupt file.
What Is OCR? How Text Recognition Works on PDFs and Photos
What is OCR? See how optical character recognition turns scans and photos into searchable text, why it makes mistakes, and how to OCR a PDF for free.
Are Online PDF Tools Safe? What Happens to Your Files
Are online PDF tools safe? See which tools upload your file and which never do, what to check before uploading, and a simple test you can run on any tool.
How to Scan Documents to PDF With Your Phone (Clear, Small Files)
Scan documents to PDF on your phone with the built-in iPhone and Android scanners, get a sharp page every time, combine pages and keep the file small.
How to Merge PDF Files on iPhone (Preview App or Safari)
How to merge PDF files on iPhone with the built-in Preview app or in Safari, choose pages, fix the order, then rename, save and share the combined PDF.
How to Split a PDF Into Multiple Files (3 Easy Ways)
How to split a PDF into multiple files by page ranges, every N pages or one page per file, plus how to size each part so it fits an upload limit.
How to Add Page Numbers to a PDF (Skip the Cover, Use Page X of Y)
How to add page numbers to a PDF: choose a format like Page 1 of 10, skip the cover, start from any number, and place the numbers well for printing.
How to Delete Pages From a PDF (Free, Without Acrobat)
How to delete pages from a PDF for free: pick pages by thumbnail or number, use the odd, even and invert shortcuts, spot blank scans, and keep files small.
How to Reduce PDF File Size: 7 Methods That Actually Work
How to reduce PDF file size seven ways: online compression, grayscale scans, cutting or splitting pages, smaller Word exports and Mac or iPhone tools.
How to Compress a PDF on Mobile (Android and iPhone)
Compress a PDF on mobile without installing an app: the browser route for Android and iPhone, the iPhone's built-in Preview option, and photo-based PDFs.
How to Compress a PDF to 500KB for Online Applications
Compress a PDF to 500 KB even when it bundles phone photos, a scanned form and a certificate: shrink each part the right way, merge, then compress once.
How to Compress a PDF Without Losing Quality
How to compress a PDF without losing quality: the lossless route that changes no pixels, and the gentlest compression level for screen, email or print.
How to Convert PDF to Word Without Losing Formatting
Convert PDF to Word without losing formatting: see what converts cleanly, which OCR setting suits a scan, and the quick fixes for anything left over.
How to Convert a Photo to PDF on Your Mobile (Android and iPhone)
Convert a photo to PDF on your mobile without an app: the iPhone and Android built-in options, combining several photos in order, and keeping it small.
How to Fit an Excel Sheet on One PDF Page (No Cut-Off Columns)
Excel to PDF cutting off columns? Fit the sheet to one page wide or one whole page, keep the text readable, and repeat the header row on every PDF page.
How to Combine Multiple Images Into One PDF (In the Right Order)
Combine multiple images into one PDF in the right order: choose page size and margins, fit receipts several to a page, fix sideways photos, and keep it small.
How to Fill a Non-Fillable PDF Form (Type, Tick, Sign, Done)
Fill a non-fillable PDF form without printing it: type into any box, add ticks, dates and a signature, keep answers aligned, and flatten before you submit.
How to Edit a PDF for Free: Text, Images, Pages and Signatures
How to edit a PDF for free: fix existing text, add images and signatures, fill in forms, remove pages or hide details, and know when Word is the better route.
How to Password Protect a PDF (Free, on Windows, Mac or Online)
Password protect a PDF for free in your browser, in Word or with Preview on a Mac. Learn which password type to use, how to pick one and how to share it.
How to Sign a PDF Electronically (Draw, Type or Upload)
Sign a PDF without printing it: draw, type or upload your signature, add initials and the date, sign on a phone, and know what a drawn signature proves.
How to Convert WebP to JPG on Windows, Mac, Phone or Online
Convert WebP to JPG on Windows, a Mac or your phone: the Paint and Preview steps, batch conversion with quality control, and what happens to transparency.
Passport Size Photo Size: Dimensions in cm, Inches and Pixels
Passport size photo size for India, the US, the UK and Schengen visas, with pixel equivalents, print vs digital rules, and how to resize a phone photo safely.
How to Reduce Image Size in KB Without Ruining the Photo
How to reduce image size in KB for forms, email and uploads: what decides the file size, how to hit an exact target like 50 KB, and when to resize first.
How to Resize a Photo to 20KB for Exam and Job Forms
Resize a photo to 20KB the reliable way: crop to the exact pixel size first, then compress to a 20 KB target so the face stays sharp and the upload passes.
How to Summarize a PDF With AI (and Check It's Accurate)
How to summarize a PDF with AI: choose the right summary type and length, focus it on what you need, check the facts, and know where your document goes.
How to Ask AI Questions About a PDF and Get Answers You Can Trust
Ask AI questions about a PDF and get answers you can check: prompts that work, how to verify the page it cites, smart follow-ups, and where AI goes wrong.
How to Translate a PDF and Keep the Layout (English, Hindi and More)
How to translate a PDF with AI: keep the layout or get only the text, handle scans, check names and numbers, and know when you need a certified translation.
How to Generate Quiz Questions From a PDF for Study or Teaching
Generate questions from a PDF with AI: why self-testing works, how many questions and which types to ask for, and how to turn them into flashcards or a quiz.
EMI Formula Explained: How to Calculate Your Loan EMI (With Examples)
The EMI calculation formula worked through step by step, how rate and tenure change your EMI and total interest, and what a prepayment really saves you.
GST Calculation Formula: Add or Remove GST With Examples
The GST calculation formula both ways: add GST to a price or remove it from a total, with worked examples, the CGST and SGST split and invoice rounding tips.
Home Loan Prepayment: Reduce EMI or Tenure? The Maths Explained
Home loan prepayment: reduce EMI or tenure? See worked numbers on a ₹40 lakh loan, the prepay-or-invest maths and the RBI rules on prepayment charges.
SIP vs Lumpsum: Which Is Better? Worked Examples in INR
SIP vs lumpsum with real maths: why a lump sum wins in steady markets, when SIP averaging helps, STP as a middle path, and a checklist to help you decide.
How to Calculate Percentage: Formulas, Shortcuts and Examples
How to calculate percentage the easy way: the formula, X% of Y, what percent one number is of another, reversing a percentage, marks, and mental shortcuts.
Margin vs Markup: The Difference and How to Price Correctly
Margin vs markup explained: both formulas side by side, a margin-to-markup conversion table, pricing for a target margin, and what fees and GST really cost.
CGPA to Percentage: The CBSE Formula and University Rules
Convert CGPA to percentage the right way: CBSE's CGPA × 9.5 rule with worked examples, why universities differ, SGPA vs CGPA, and how to convert back.
Discount Calculation Formula: Find the Real Price and Real Discount
The discount calculation formula both ways, with worked examples: discount %, original price, stacked offers, bank offer caps, GST and which deal is best.
How Many Pages Is 1000 Words? (Single and Double Spaced)
How many pages is 1000 words? About 1.4 pages single-spaced or 2.8 double-spaced in 12-pt Times New Roman, plus a table from 500 to 5,000 words.
How to Create a Strong Password You Can Actually Remember
How to create a strong password: current NIST rules in plain English, the maths of random passwords vs passphrases, and the patterns attackers try first.
How to Count Words in a PDF (Accurately, Even Scanned Files)
How to count words in a PDF accurately: extract and count the text, stop headers and page numbers inflating the total, handle scans and see what counts.
How to Create a UPI QR Code for Payments (Free, With Amount)
How to create a UPI QR code for your UPI ID, with or without a fixed amount: what the code holds, how to test it, print sizes, logos and the scam to avoid.
Every article, by topic
All 110 guides on one page.
PDF Basics
- PDF Not Opening? Fixes for Windows, Mac, Android and iPhone
- What Is a PDF File? How PDFs Work and Why Everyone Uses Them
- What Is OCR? How Text Recognition Works on PDFs and Photos
- Are Online PDF Tools Safe? What Happens to Your Files
- How to Scan Documents to PDF With Your Phone (Clear, Small Files)
- Why Can't I Edit My PDF? 6 Reasons and How to Fix Each
- PDF vs DOCX: Which Format Should You Use and When?
- What Is PDF/A? The Archival PDF Format Explained Simply
Merge, Split & Organize
- How to Merge PDF Files on Any Device (Free, No Software)
- How to Merge PDF Files on iPhone (Preview App or Safari)
- How to Split a PDF Into Multiple Files (3 Easy Ways)
- How to Add Page Numbers to a PDF (Skip the Cover, Use Page X of Y)
- How to Delete Pages From a PDF (Free, Without Acrobat)
- How to Extract Pages From a PDF and Save Them as a New File
- How to Rearrange Pages in a PDF (Drag, Drop, Done)
- How to Rotate a PDF and Save It Permanently
- How to Combine Odd and Even Pages Into One PDF (Duplex Scans)
- How to Crop a PDF: Trim Margins or Keep Just One Area
- How to Insert a Page Into a PDF (Blank Page, Scan or Another PDF)
Compress & Optimize
- How to Compress a PDF to 100KB (or Any Size Limit) for Online Forms
- How to Compress a PDF to 1MB or Less (Resumes, Reports, Forms)
- How to Compress a PDF to 200KB, Even a Multi-Page Scan
- How to Reduce PDF File Size: 7 Methods That Actually Work
- How to Compress a PDF on Mobile (Android and iPhone)
- How to Compress a PDF to 500KB for Online Applications
- How to Compress a PDF Without Losing Quality
- How to Compress a Scanned PDF and Keep It Readable
- How to Convert a PDF to Black and White (Grayscale) for Free
- PDF Too Large to Email? 5 Ways to Send It Anyway
- How to Reduce PDF Size on a Mac (Without Preview's Blurry Results)
- Why Is My PDF So Large? Common Causes and Quick Fixes
Convert to & from PDF
- How to Convert a Bank Statement PDF to Excel (Clean Rows, Real Numbers)
- How to Convert PDF to Word Without Losing Formatting
- How to Convert a Photo to PDF on Your Mobile (Android and iPhone)
- How to Fit an Excel Sheet on One PDF Page (No Cut-Off Columns)
- How to Combine Multiple Images Into One PDF (In the Right Order)
- How to Convert Any Document to PDF: Word, Excel, Images and More
- How to Convert PDF to JPG in High Quality (DPI Explained Simply)
- How to Convert a Scanned PDF to an Editable Word Document
- How to Copy Text From a PDF (Even Scanned or Protected Files)
- How to Print to PDF on Windows, Mac, iPhone and Android
- Word to PDF Without Losing Formatting: Fonts, Images and Links
- How to Convert a Jupyter Notebook to PDF (Without LaTeX Errors)
- How to Convert PDF to Editable PPT Slides (3 Modes Compared)
- How to Convert PPT to PDF With Speaker Notes or Handouts
- How to Convert a Word Document to PDF on Your Phone
- How to Read a PDF on Kindle Without Squinting
- How to Save a Webpage as a PDF (No Ads, Cut-Offs or Blank Pages)
Edit, Sign & Secure
- Aadhaar Card PDF Password: Format, Examples and How to Remove It
- How to Fill a Non-Fillable PDF Form (Type, Tick, Sign, Done)
- How to Edit a PDF for Free: Text, Images, Pages and Signatures
- How to Password Protect a PDF (Free, on Windows, Mac or Online)
- How to Sign a PDF Electronically (Draw, Type or Upload)
- How to Remove a Password From a PDF You Can Already Open
- How to Add Text to a PDF (Type Anywhere, on Any Device)
- How to Edit Existing Text in a PDF (and Match the Font)
- Electronic Signature vs Digital Signature: What's the Difference?
- How to Redact a PDF Properly (So the Text Is Really Gone)
- How to Add a Watermark to a PDF (Text or Logo, Free)
- How to Compare Two PDF Files and Spot What Changed
- How to Make a PDF Non-Editable (3 Methods, From Light to Locked)
- How to Remove Metadata From a PDF Before You Share It
- What Does Flattening a PDF Mean? When and How to Do It
Image Tools
- How to Convert WebP to JPG on Windows, Mac, Phone or Online
- Passport Size Photo Size: Dimensions in cm, Inches and Pixels
- How to Reduce Image Size in KB Without Ruining the Photo
- How to Resize a Photo to 20KB for Exam and Job Forms
- How to Resize Your Signature for Online Forms (10KB to 20KB)
- How to Convert PNG to JPG Without Black Backgrounds
- How to Make a Photo Background White for Products and ID Photos
- PNG vs JPG: Which Image Format Should You Use?
- How to Resize an Image Without Losing Quality (or Stretching It)
- How to Change the DPI of an Image (and When It Actually Matters)
- How to Remove Location and EXIF Data From a Photo Before Sharing
- How to Resize Multiple Images at Once (Free Batch Resize)
AI Tools
- How to Summarize a PDF With AI (and Check It's Accurate)
- How to Ask AI Questions About a PDF and Get Answers You Can Trust
- How to Translate a PDF and Keep the Layout (English, Hindi and More)
- How to Generate Quiz Questions From a PDF for Study or Teaching
- How to Have a PDF Read Aloud (or Turn It Into an MP3)
- How to Transcribe Audio to Text for Free (Meetings, Lectures, Voice Notes)
Finance Calculators
- CAGR Formula With Examples: How to Calculate Growth Rate
- Compound Interest Formula With Examples (Yearly, Quarterly, Monthly)
- EMI Formula Explained: How to Calculate Your Loan EMI (With Examples)
- GST Calculation Formula: Add or Remove GST With Examples
- Home Loan Prepayment: Reduce EMI or Tenure? The Maths Explained
- SIP vs Lumpsum: Which Is Better? Worked Examples in INR
- CTC vs In-Hand Salary: Why Your Take-Home Pay Is Lower
- FD vs RD: Which Earns More? Interest Formulas and Examples
- Home Loan Eligibility on Salary: How Much Can You Borrow?
- How EPF Interest Is Calculated: Monthly Example With Numbers
- SIP Calculation Formula: How Your SIP Returns Are Worked Out
- Flat vs Reducing Interest Rate: Why 8% Flat Isn't 8%
- Gratuity Calculation Formula With Examples (and What Changed)
- How PPF Interest Is Calculated (and Why the 5th of the Month Matters)
- Rule of 72: How Long Will Your Money Take to Double?
Everyday Calculators
- How to Calculate Percentage: Formulas, Shortcuts and Examples
- Margin vs Markup: The Difference and How to Price Correctly
- CGPA to Percentage: The CBSE Formula and University Rules
- Discount Calculation Formula: Find the Real Price and Real Discount
- Percentage Increase and Decrease Formula (With Real Examples)
- BMI Formula: How to Calculate BMI and What It Means for Indians
- How to Calculate Age From Date of Birth (Exact Years, Months, Days)
- How to Calculate Hours Worked (Breaks, Night Shifts and Overtime)
Text & Developer Tools
- How Many Pages Is 1000 Words? (Single and Double Spaced)
- How to Create a Strong Password You Can Actually Remember
- How to Count Words in a PDF (Accurately, Even Scanned Files)
- How to Create a UPI QR Code for Payments (Free, With Amount)
- How to Fix Invalid JSON: Common Errors and Their Fixes
- What Is Base64 Encoding? How It Works, With Examples