Guides & Articles
ToolForge's tools solve one problem each. These guides cover the questions that surround them — what a file format actually contains, why a conversion fails, which of two options to choose, how to do the job when the obvious software is not available.
Each one is written because somebody needed that specific answer, and each is grouped into a topic alongside the tools it relates to. There is no publishing schedule and no archive to pad out: a guide exists here when it has something to say that a tool page cannot.
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HEIC vs JPG: What's the Difference?
HEIC compresses more efficiently than JPG but almost nothing outside Apple opens it easily. What each format actually trades off, and which to shoot.
How to Convert HEIC to JPG
Convert iPhone HEIC photos to JPG for free in your browser: which settings to use, what survives conversion, and how to handle a whole camera roll at once.
How to Stop Your iPhone From Saving Photos as HEIC
One setting switches new iPhone photos to JPEG instead of HEIC. Where it is, exactly what it changes, and what it does not do to your existing library.
What Is a HEIC File?
HEIC is the photo format every iPhone has defaulted to since 2017. What it actually stores, why so little non-Apple software opens it, and what to do about it.
CR3 vs JPG: What Is the Difference?
CR3 keeps your sensor data, JPG keeps a finished picture. What each one costs you in card space, editing freedom and compatibility, and when to shoot which.
How Image Compression Works
Why a photo can lose 80% of its bytes and look identical: what lossy compression discards, how quality settings behave, and why PNG ignores them entirely.
How to Compress an Image
Compress JPG, PNG or WebP files in your browser: which preset to use, when to set a target size in KB, and the order of operations that saves the most.
How to Compress Images Without Losing Quality
Truly lossless compression, and visually lossless compression, are different things. Which to use per image type, and where the quality thresholds actually sit.
How to Convert CR3 to JPG
Turn Canon CR3 raw files into JPGs without installing anything: the browser route step by step, plus what to set for quality, size, orientation and metadata.
How to Format JSON
Turn minified JSON into something readable, or the reverse. What formatting changes about your data, what it silently normalises, and when to minify.
JPG vs PNG vs WebP: Which Should You Use?
A decision table plus the published figures: WebP is 25–34% smaller than JPEG and 26% smaller than PNG. When each format still wins, and where AVIF fits.
What Is a CR3 File?
CR3 is Canon's raw photo format, introduced in 2018. Here is what is inside one of these files, why most software cannot open them, and what to do with them.
What Is JSON?
JSON is a text format for structured data, with six value types and a grammar you can read in an afternoon. What it is, where it came from, and where it bites.
Why Your JSON Is Invalid — Every Error Explained
Match the parser error to its cause: unexpected token, unexpected end of input, bad control character, and the invisible BOM. With the fix for each.
Browse by topic
All topicsWhy an iPhone photo will not open on Windows, what a HEIC file actually is, how to convert it, and how to stop your phone from writing them in the first place.
7 guides
Why lossy compression works, which format to use, what image size a web page actually needs, and why a file is still too big after compressing it.
8 guides
What JSON is, the syntax rules that actually trip people up, why a parser rejected your file, and how JSON compares with XML and YAML.
8 guides
Everything about Canon's CR3 raw format: what the files contain, why software struggles to open them, and how to get shareable JPGs out of them.
6 guides
All guides
29 of 29 guides
- ComparisonHEIC & iPhone Photos
HEIC vs JPG: What's the Difference?
HEIC compresses more efficiently than JPG but almost nothing outside Apple opens it easily. What each format actually trades off, and which to shoot.
- How-toHEIC & iPhone Photos
How to Convert HEIC to JPG
Convert iPhone HEIC photos to JPG for free in your browser: which settings to use, what survives conversion, and how to handle a whole camera roll at once.
- How-toHEIC & iPhone Photos
How to Open HEIC Files on Windows and Android
Windows and Android show a blank thumbnail instead of your iPhone photos. Here is the actual fix for each — usually a free codec, not new software.
- How-toHEIC & iPhone Photos
How to Stop Your iPhone From Saving Photos as HEIC
One setting switches new iPhone photos to JPEG instead of HEIC. Where it is, exactly what it changes, and what it does not do to your existing library.
- ExplainerHEIC & iPhone Photos
What Happens to Live Photos When You Convert HEIC to JPG?
Converting a Live Photo gives a single still frame, never the motion — not a converter fault. Here is why, and what "multiple frames" in a HEIC really means.
- GuideHEIC & iPhone Photos
What Is a HEIC File?
HEIC is the photo format every iPhone has defaulted to since 2017. What it actually stores, why so little non-Apple software opens it, and what to do about it.
- TroubleshootingHEIC & iPhone Photos
Why Won't My HEIC File Open or Convert?
A HEIC that refuses to open or convert is usually one of five specific problems. Match the message to the cause before you assume the file is broken.
- ComparisonCanon CR3 & RAW Photos
CR3 vs JPG: What Is the Difference?
CR3 keeps your sensor data, JPG keeps a finished picture. What each one costs you in card space, editing freedom and compatibility, and when to shoot which.
- GuideImage Compression & Formats
How Image Compression Works
Why a photo can lose 80% of its bytes and look identical: what lossy compression discards, how quality settings behave, and why PNG ignores them entirely.
- How-toImage Compression & Formats
How to Compress an Image
Compress JPG, PNG or WebP files in your browser: which preset to use, when to set a target size in KB, and the order of operations that saves the most.
- How-toImage Compression & Formats
How to Compress Images Without Losing Quality
Truly lossless compression, and visually lossless compression, are different things. Which to use per image type, and where the quality thresholds actually sit.
- Use caseCanon CR3 & RAW Photos
How to Convert Canon RAW Files Without Photoshop
You do not need an Adobe subscription to get usable photos out of Canon raw files. The free routes, what each one is good at, and what you actually give up.
- How-toCanon CR3 & RAW Photos
How to Convert CR3 to JPG
Turn Canon CR3 raw files into JPGs without installing anything: the browser route step by step, plus what to set for quality, size, orientation and metadata.
- How-toJSON
How to Escape Strings in JSON
Escaping JSON is easy until there are layers. How to escape a string, how to nest JSON inside JSON, and how to get a payload through a shell intact.
- How-toJSON
How to Format JSON
Turn minified JSON into something readable, or the reverse. What formatting changes about your data, what it silently normalises, and when to minify.
- How-toCanon CR3 & RAW Photos
How to Open CR3 Files on Windows, Mac and Mobile
Your computer shows blank icons instead of photos. Here is how to open Canon CR3 files on Windows, macOS, iPhone and Android, and what to do when nothing works.
- How-toJSON
How to Validate JSON
Validating JSON answers three different questions: is it well-formed, does it match a schema, and is the data right. How to check each, and where each stops.
- Best practicesImage Compression & Formats
Image Optimization Best Practices
The nine things that actually make images fast, in order of impact — right dimensions, right format, lazy loading everything except the one image you must not.
- ComparisonImage Compression & Formats
JPG vs PNG vs WebP: Which Should You Use?
A decision table plus the published figures: WebP is 25–34% smaller than JPEG and 26% smaller than PNG. When each format still wins, and where AVIF fits.
- ReferenceJSON
JSON Syntax Reference
Every JSON syntax rule in one place: the six value types, the escape sequences, what numbers may contain, and the rules people think exist but do not.
- ComparisonJSON
JSON vs XML: Which Should You Use?
JSON is smaller and easier to parse; XML carries attributes, namespaces and real validation. Where each one wins, and why the choice is rarely close any more.
- ComparisonJSON
JSON vs YAML: What Is the Difference?
YAML is JSON with comments, less punctuation and more ways to shoot yourself. What differs, why config chose YAML, and the traps in converting between them.
- ExplainerImage Compression & Formats
What Image Size Should You Use on a Website?
Pixel dimensions, file size and DPI are three different things, and only two of them matter on the web. The sizes to use, and why 300 DPI is meaningless here.
- GuideCanon CR3 & RAW Photos
What Is a CR3 File?
CR3 is Canon's raw photo format, introduced in 2018. Here is what is inside one of these files, why most software cannot open them, and what to do with them.
- GuideJSON
What Is JSON?
JSON is a text format for structured data, with six value types and a grammar you can read in an afternoon. What it is, where it came from, and where it bites.
- ExplainerImage Compression & Formats
What Is the Difference Between Lossy and Lossless Compression?
Lossless keeps every pixel; lossy discards what you cannot see. What each one actually promises, why lossless is not "better quality", and which to pick.
- TroubleshootingCanon CR3 & RAW Photos
Why Your CR3 File Won't Convert (and How to Fix It)
A CR3 that refuses to convert is usually one of five specific problems. Match the error message to the cause, and the fix, before you retry the file.
- TroubleshootingImage Compression & Formats
Why Your Image Is Still Too Large After Compressing
Six reasons compression did not shrink your file: a PNG that stayed a PNG, dimensions rather than quality, an already-optimised source, or a lying upload limit.
- TroubleshootingJSON
Why Your JSON Is Invalid — Every Error Explained
Match the parser error to its cause: unexpected token, unexpected end of input, bad control character, and the invisible BOM. With the fix for each.
