VektraTool guides
Guides to Images, Calculations, Text and Code
Step-by-step help with real problems, such as getting a photo under 50 KB, working out a discount on a discount or fixing invalid JSON. Each guide shows worked examples and links to the free tool that does the job.
34 guides · 4 topics · Last updated
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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.
By Akmal AliUpdated 4 min read
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Showing 1–12 of 34 guides
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.
8 min readTry Image Dimensions CheckerImage 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.
14 min readTry Add Watermark to ImageCalculator 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.
6 min readTry Salary CalculatorImage 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.
14 min readTry Image Metadata ViewerImage 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.
12 min readTry Image Metadata ViewerImage 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.
9 min readTry Image ResizerCalculator 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.
4 min readTry Discount CalculatorCalculator 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.
4 min readTry Profit Margin CalculatorText 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.
4 min readTry Word CounterText 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.
4 min readTry Character CounterUtility 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.
4 min readTry JSON FormatterUtility 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.
5 min readTry Base64 Encoder / Decoder
Browse all 34 guides by topic
Every title on one page, A–Z within each topic.
Image Tools (15)
- Does PNG to JPG Lose Quality? When to Convert and What Changes
- How to Add a Watermark to an Image Without Ruining the Design
- How to Check Image DPI and PPI, and What They Mean
- How to Check Image Metadata and What It Reveals
- How to Combine Photos Into One PDF on Your Phone
- How to Compress an Image Without Losing Too Much Quality
- How to Convert HEIC to JPG on iPhone, Mac and Windows
- How to Resize an Image Without Distorting It
- Image Aspect Ratios: Work Them Out and Choose One
- Image Metadata Explained: EXIF, Dimensions, Camera Data and Privacy
- Image Size vs Dimensions: What’s the Difference?
- JPG vs PNG vs WebP: Which Image Format Should You Use?
- JPG vs WebP: How Much Smaller, and When to Convert
- Passport Photo Rules: Sizes, Background and Common Rejections
- Why Won’t My Image Go Under 50KB or 100KB?
Calculator Tools (8)
- BMI by Hand: The Formula, Worked Examples and Adult Categories
- Calculating Age by Hand: Leap Days, Cut-off Dates and Spreadsheets
- Discount Maths: Stacked Discounts, Working Backwards and Tax
- Gross vs Net Salary: What Comes Off Your Pay, and in What Order
- How Compound Interest Works, With Real Numbers
- How to Calculate Percentages by Hand, Backwards and Over Several Steps
- Profit Margin vs Markup: How to Calculate Both
- The EMI Formula Worked Out by Hand, With a Spreadsheet Version
Text Tools (3)
Utility Tools (8)
- How Long Should a Password Be?
- How to Create SEO-Friendly URL Slugs
- How to Encode and Decode Base64, and What It’s For
- How to Encode and Decode URLs: Percent-Encoding Explained
- JSON Syntax Errors Explained, and How to Fix Them
- Unix Timestamp Explained: How to Convert Unix Time
- What Is a UUID? Versions, Uniqueness and When to Use One
- What Size Should a Printed QR Code Be?
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