Akmal Ali
Lahore, PakistanAkmal Ali runs VektraTool from Lahore, Pakistan. He builds and maintains every tool on the site and writes its guides, checking each worked example against the tools’ own results before it is published.
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Worked examples and measured file sizes come from running the site’s own tools with their default settings, and are measured again when a tool’s output changes.
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Rules set by others, such as passport photo sizes, SMS limits or password guidance, are taken from the organisation that sets them and linked where they are used.
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Health and money guides show the formula and its limits, so you can check the arithmetic. They are not medical, financial or credit advice.
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Published Guides
Guides & articles by Akmal Ali (34)
Practical walkthroughs, mathematical breakdowns, and tool tutorials written and verified by Akmal Ali.
Image Tools
Image Size vs Dimensions: What’s the Difference? (new)
Image dimensions are pixels, image size is usually bytes, and they can move in opposite directions. What each means, what changes it and which one a form wants.
Image Tools
How to Add a Watermark to an Image Without Ruining the Design (new)
Where to place a watermark, how large and how transparent to make it, and how to keep it readable without covering the subject, with a worked example.
Calculator Tools
Gross vs Net Salary: What Comes Off Your Pay, and in What Order (new)
What gross and net salary include, which deductions come off and in what order, a worked payslip, and how to check that your own payslip adds up.
Image Tools
Image Metadata Explained: EXIF, Dimensions, Camera Data and Privacy (new)
What image metadata is, how EXIF, XMP and IPTC differ, where each format stores them, why photos lose or change metadata, and what metadata can and can’t prove.
Image Tools
How to Check Image Metadata and What It Reveals (new)
Check the metadata in a photo and read what it says: camera, settings, dates and GPS location, what each field means, and what to check before you share.
Image Tools
How to Resize an Image Without Distorting It (new)
Why images stretch or squash when they are resized, how width, height and aspect ratio fit together, and a workflow that keeps every photo in proportion.
Calculator ToolsUpdated
Discount Maths: Stacked Discounts, Working Backwards and Tax
Work out a sale price and the amount saved, find a discount percentage from two prices, undo a discount, and see why stacked discounts don’t add up.
Calculator ToolsUpdated
Profit Margin vs Markup: How to Calculate Both
Profit margin and markup explained with worked examples: gross, operating and net margin, converting markup to margin, and pricing for a target margin.
Text ToolsUpdated
What Counts as a Word? Hyphens, Numbers and Word Limits
Where to find a word count, how hyphens, numbers and dashes are counted, and how to work with word limits for essays, articles and speeches.
Text ToolsUpdated
What Counts as a Character? Spaces, Emoji and Limits
What counts as a character, when spaces count, why emoji can count twice, and how to write within limits for SMS, page titles, posts and form fields.
Utility ToolsUpdated
JSON Syntax Errors Explained, and How to Fix Them
JSON syntax explained with valid and invalid examples: formatting vs minifying, indentation, and how to fix trailing commas, single quotes and other errors.
Utility ToolsUpdated
How to Encode and Decode Base64, and What It’s For
How Base64 turns data into text, why it ends in = signs, where it’s used, how to encode and decode it, and why Base64 is encoding, not encryption.
Utility ToolsUpdated
Unix Timestamp Explained: How to Convert Unix Time
What Unix time and the epoch are, 10-digit vs 13-digit timestamps, converting between timestamps and dates in UTC and local time, with code examples.
Utility ToolsUpdated
What Is a UUID? Versions, Uniqueness and When to Use One
What a UUID is, how to read its version and variant, UUID versions 1, 4 and 7, how unique random UUIDs are, and how they compare with database IDs.
Utility ToolsUpdated
How to Create SEO-Friendly URL Slugs
Write clean URL slugs: lowercase, hyphens, no punctuation, accents and other scripts, sensible length, good and poor examples, and changing slugs safely.
Utility ToolsUpdated
How to Encode and Decode URLs: Percent-Encoding Explained
How percent-encoding works, which characters need it, encoding a value vs a whole URL, %20 vs +, and the mistakes that break links and query strings.
Image ToolsUpdated
How to Convert HEIC to JPG on iPhone, Mac and Windows
What HEIC files are and every way to turn them into JPGs: in Safari, on the iPhone itself, on a Mac and on Windows, plus fixes for common problems.
Image ToolsUpdated
Passport Photo Rules: Sizes, Background and Common Rejections
Take, crop and print a passport-size photo at home: official sizes, lighting and background tips, and the mistakes that get photos rejected.
Image ToolsUpdated
Does PNG to JPG Lose Quality? When to Convert and What Changes
Convert PNG to JPG with no visible quality loss: which images to convert, the quality setting to use, and what happens to transparent backgrounds.
Image ToolsUpdated
JPG vs WebP: How Much Smaller, and When to Convert
Why WebP makes web pages faster, how to convert JPG to WebP at the right quality, how to add WebP to a site, and when to keep JPG.
Image ToolsUpdated
How to Check Image DPI and PPI, and What They Mean
Check an image’s DPI on any device, understand DPI vs PPI, and work out how many pixels you need to print at 300 PPI, with a table of print sizes.
Image ToolsUpdated
Image Aspect Ratios: Work Them Out and Choose One
Which aspect ratio to use for prints, video, social posts and web pages, how to work one out, and how much of a photo each print size crops off.
Calculator ToolsUpdated
BMI by Hand: The Formula, Worked Examples and Adult Categories
The BMI formula in kg and m or lb and in, worked examples, the adult BMI categories, and what BMI can and can’t tell you about your health.
Calculator ToolsUpdated
The EMI Formula Worked Out by Hand, With a Spreadsheet Version
The EMI formula step by step, with worked loan examples, total interest and repayment, how rate and tenure change the cost, and flat vs reducing rates.
Calculator ToolsUpdated
How Compound Interest Works, With Real Numbers
The compound interest formula explained with worked examples, the effect of compounding frequency, simple vs compound interest, deposits and the rule of 72.
Utility ToolsUpdated
What Size Should a Printed QR Code Be?
How link length, error correction and module size decide how big to print a QR code, with measured sizes, contrast rules and the right file format.
Utility ToolsUpdated
How Long Should a Password Be?
What the NIST standard says about password length, why length beats complexity, and how long your passwords and passphrases should be.
Text ToolsUpdated
How Many Words Is a Page?
How many words fit on a page single- and double-spaced, what changes the count, and how to convert a page limit into words.
Image ToolsUpdated
How to Combine Photos Into One PDF on Your Phone
Turn several photos or scans into a single PDF in your phone’s browser, in the right order and small enough for upload limits.
Image ToolsFeatured
How to Compress an Image Without Losing Too Much Quality
Practical steps to make images much smaller while keeping them sharp: resizing, choosing the right format and picking a sensible quality setting.
Image ToolsUpdated
Why Won’t My Image Go Under 50KB or 100KB?
What “under 50KB” or “under 100KB” means in bytes, what fits in that size, the other rules forms set, and what to do when an image won’t fit.
Calculator ToolsUpdated
Calculating Age by Hand: Leap Days, Cut-off Dates and Spreadsheets
Work out an exact age in years, months and days by hand, with a worked example and the rules for month ends and leap-day birthdays.
Calculator ToolsUpdated
How to Calculate Percentages by Hand, Backwards and Over Several Steps
The four percentage formulas, how to work back to an original amount, why percentages over several steps multiply, and the spreadsheet formulas.
Image ToolsUpdated
JPG vs PNG vs WebP: Which Image Format Should You Use?
How JPG, PNG and WebP differ in compression, transparency, file size and compatibility, which to choose, and when converting JPG to PNG helps.