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Image Guides & Tutorials

Everything we know about making images smaller, faster, and safer — explained in plain English. Start with the cornerstone guides, then dive into focused how-tos by topic. Every technique here runs entirely in your browser: no uploads, no sign-up, no servers.

How Image Compression Actually Works: Lossy, Lossless, and Every Format

A plain-English tour of what really happens when you compress an image — how JPEG throws away detail your eyes ignore, how PNG shrinks files with zero loss, and how to pick the right trade-off.

10 min read

JPG vs PNG vs WebP vs AVIF: Which Image Format Should You Use?

A practical decision guide to the formats that matter — JPG, PNG, WebP, AVIF, GIF and SVG — what each is actually good at, and a simple rule for picking the right one every time.

9 min read

How to Resize Images Without Losing Quality

What actually happens when you resize an image, why shrinking is safe but enlarging is not, the DPI myth, and how to resize for the web, print, and social without softening your photos.

9 min read

Why In-Browser Image Tools Are More Private (and How Client-Side Processing Works)

Most "free online" image tools upload your photos to a server. Client-side tools do everything on your own device. Here is the difference, how it works technically, and how to verify it yourself.

8 min read

How to Optimize Images for Website Speed & Core Web Vitals

Images are usually the heaviest thing on a web page. Here is a practical, order-of-operations playbook to make them load fast, pass Core Web Vitals, and help your SEO — without wrecking quality.

10 min read

How to Compress an Image to an Exact File Size (100 KB, 500 KB, 2 MB)

Upload forms demand "under 200 KB" and give you no way to get there. This guide explains why a quality slider alone will not hit a number, and gives you a repeatable method that does — for any target, any format.

13 min read

Passport and Visa Photo Requirements: A Practical Guide to Getting It Accepted

Why ID photos get rejected, what the specs actually mean, and how to prepare a compliant passport or visa photo yourself — including the size, background, and framing rules that differ by country.

12 min read

Preparing Images for Print: DPI, Resolution, and Why Screen Rules Do Not Apply

Why a photo that looks perfect on screen prints blurry, what DPI really means, and how to work out the exact pixel dimensions you need for any print size — from a business card to A3.

12 min read

What Platforms Do to Your Images (and How to Upload So They Survive)

Every platform re-compresses what you upload. Understanding what Instagram, WhatsApp, LinkedIn, and the rest actually do to your file explains why your images look worse than the original — and how to upload so they hold up.

12 min read

Reference tables

The numbers you came for, each in one place rather than spread across a page per value — upload limits, pixel dimensions, platform sizes and official photo specs.

Compress an image to a specific file size

Hit an exact upload limit — 20KB, 50KB, 100KB, 1MB or anything between. Which target to aim for, what each one costs you in quality, and how to get there in one step.

Reference

Compress a PDF to a specific file size

Get a PDF under 100KB, 500KB, 2MB or any other upload cap. What actually drives PDF size, which targets are realistic, and when compression will not be enough.

Reference

Standard image dimensions and print sizes

Every common pixel dimension and print size in one table — Full HD, 4K, A4, US Letter, photo prints — plus how DPI decides the pixel count you actually need.

Reference

Social media image sizes

Current image dimensions for Instagram, YouTube, Facebook, LinkedIn, TikTok, X, Pinterest, Threads, Discord and Twitch — with the safe-area rules that actually matter.

Reference

Passport and visa photo sizes by country

Official passport photo dimensions for the US, UK, EU, India, Canada, Australia, China, Japan, Schengen and more — plus the rules that get photos rejected.

Reference

Marketplace product image requirements

Image size, background and framing rules for Amazon, Shopify, Etsy, eBay, WooCommerce, Vinted, Depop and Poshmark — in one comparison table.

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Browse by topic

Compress & Optimize

Shrink image (and video) files for the web, email, and upload limits — and understand exactly how compression works so you never sacrifice quality you did not need to.

Convert & Formats

JPG, PNG, WebP, AVIF, HEIC, SVG — what each format is for and how to convert between them without losing quality or breaking transparency.

Resize & Crop

Change dimensions and aspect ratios the right way — shrink freely, enlarge carefully, and hit exact sizes for print, marketplaces, and documents.

Edit & Enhance

Remove backgrounds and objects, upscale, add text, filters, watermarks, and more — all in your browser, no design software required.

Privacy & Metadata

Why processing images on your own device beats uploading them, plus how to strip hidden EXIF/location data and hide faces before you share.

Web, Social & Developers

Get images right for websites and every social platform, plus developer essentials — favicons, Open Graph images, QR codes, and OCR.

Put it into practice

Free, private, browser-based image tools — no uploads, no account.

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