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34 guides on PDF editing, 3D and CAD formats, image and video compression, and keeping CSV, JSON and YAML data clean.

PDF editing and documents

Editing, redacting, comparing and preparing PDFs — including the things that quietly go wrong.

How to Merge PDFs Without Uploading Them Anywhere

Online PDF mergers put your contracts and invoices on someone else’s server. Your browser can do the same job locally — here is how, and how to verify it.

August 18, 2026 · 5 min read

JPG to PDF: Page Sizes, Quality and Scanning Tips

Turning photos and scans into a PDF sounds trivial until the pages come out the wrong size. A practical guide to page geometry, DPI and file size.

August 18, 2026 · 5 min read

How to Edit a PDF Without Uploading It Anywhere

Add text, a handwritten signature, highlights or images to a PDF locally - and understand what a browser PDF editor can and cannot safely change.

August 17, 2026 · 6 min read

PNG vs WebP vs JPEG: Which Image Format Should You Use?

A practical guide to choosing between PNG, WebP and JPEG: compression, transparency, quality and browser support — with a free converter to switch between them.

August 17, 2026 · 5 min read

CSV vs JSON: Which Data Format Should You Use?

CSV and JSON solve different problems: flat tables vs nested structures. When each wins, common conversion pitfalls, and a free browser-based converter.

August 17, 2026 · 5 min read

How to Format and Validate JSON (and Find the Actual Error)

A practical guide to JSON syntax errors, formatting vs minifying, key sorting and safe handling of API payloads with a private browser tool.

August 17, 2026 · 5 min read

STL, OBJ, 3MF or AMF: The Best File Format for 3D Printing

Which file format should you actually print from? A practical ranking of STL, OBJ, 3MF and AMF for FDM and resin printing, with free conversion tools.

August 16, 2026 · 6 min read

IGES vs STEP: Which CAD Exchange Format Should You Use?

IGES and STEP both move CAD data between systems, but they are generations apart. When IGES still appears, why STEP usually wins, and how to convert both for free.

August 15, 2026 · 5 min read

How to Make a Scanned PDF Searchable

A scanned PDF is a picture of a document, not a document. Here is what OCR actually does to it, how accurate to expect, and how to run it without uploading the file.

August 14, 2026 · 7 min read

How to Redact a PDF Properly

A black rectangle drawn over text hides nothing — the words are still in the file. Here is why that keeps leaking documents, and how real redaction differs.

August 12, 2026 · 7 min read

How to Compare Two PDF Versions

Someone sent back a revised contract with no track changes. Here is how to find every altered line between two PDFs, and where automated comparison misleads you.

August 10, 2026 · 6 min read

How to Compress a PDF Without Wrecking It

Most PDF bloat comes from images, not text. Here is how to find what is actually large, what each compression method costs you, and when not to compress at all.

August 7, 2026 · 6 min read

Filling PDF Forms, and Why You Should Flatten Them

Interactive PDF forms lose their answers in the wrong reader, and keep data you thought you deleted. Here is what filling really does and when to flatten.

August 5, 2026 · 6 min read

Bates Numbering and Watermarks Explained

Bates numbers make every page in a disclosure citable, and watermarks mark a draft as a draft. What each convention requires, and the mistakes that break a set.

August 2, 2026 · 6 min read

glTF vs GLB vs OBJ: Choosing a 3D Format for the Web

Which 3D format should you ship on the web? A practical comparison of glTF, GLB and OBJ — file size, materials, loading speed — with free conversion tools.

July 22, 2026 · 6 min read

STEP vs STL: Which 3D File Format Should You Use?

STEP stores exact CAD geometry, STL stores triangles. Understand the difference, when each format wins, and how to convert between them for free.

July 5, 2026 · 6 min read

3D and CAD formats

Choosing between exchange formats, converting them without losing what matters, and reading what came out.

How to Read G-code: A Practical Guide

What the commands in a .gcode file mean, which ones matter, and how previewing the toolpath catches failed prints before they waste filament.

August 18, 2026 · 6 min read

What Is a GLB File and How Do You Open One?

GLB is the binary form of glTF — the standard format for 3D on the web and in AR. What GLB files contain, how to open them free, and how to convert to and from GLB.

August 17, 2026 · 4 min read

3MF vs STL: Should You Switch for 3D Printing?

3MF fixes almost everything wrong with STL — units, colors, watertightness, file size. A practical comparison, plus free tools to convert STL to 3MF.

August 14, 2026 · 5 min read

How to Open a STEP File Without CAD Software

You received a .step or .stp file but have no CAD program installed. Here are your options — including a free browser-based STEP viewer that needs no install.

August 13, 2026 · 4 min read

Tessellation Quality Explained: Linear and Angular Deflection

What do tessellation quality settings actually control? Linear and angular deflection explained with practical presets for 3D printing, rendering and web delivery.

August 11, 2026 · 5 min read

Is Online CAD Conversion Safe? What Happens to Your Files

Most online CAD converters upload your intellectual property to unknown servers. Learn what actually happens to uploaded files and how client-side conversion avoids the risk.

August 2, 2026 · 5 min read

How to Reduce a 3D Model’s Polygon Count

A 40 MB mesh that stalls the browser usually has far more triangles than it needs. What decimation does, what it destroys, and how far you can safely go.

July 25, 2026 · 7 min read

How to Convert STEP to STL for 3D Printing (Free, No Upload)

A practical guide to converting STEP files to printable STL: tessellation quality, common pitfalls, and a free browser-based converter that keeps files private.

July 14, 2026 · 5 min read

Images

Compression, resizing, favicons and the metadata your photos carry without telling you.

Video and audio

Encoding trade-offs, and when a different format is the real answer.

Data and config files

CSV, JSON, YAML and XML — which to use, and how to keep them clean.

Frequently asked questions

Which guide should I read before converting a CAD file?

Start with STEP vs STL if you are deciding which format to send, and tessellation quality explained if you already know you need a mesh — that setting is the one irreversible decision in the conversion and the default is rarely the right answer for both printing and rendering.

I need to remove information from a PDF before sending it. Where do I start?

Read “How to redact a PDF properly”. Drawing a black rectangle over text does not remove it — the words stay in the file and can be selected, searched and copied straight back out. The guide explains what real redaction requires and what to verify before the document leaves your hands.

My file is too large to email. Which guide covers that?

It depends on the file. For documents, “How to compress a PDF without wrecking it” explains why the weight is almost always images rather than text. For images, “How to compress images for the web”. For video, “How to compress a video in your browser”, which covers why resolution is the first dial to turn and bitrate the last.

Which format should I send someone for 3D printing?

STL still works everywhere and 3MF is the better modern choice, since it carries units, colour and multiple objects in one file. “Best 3D file format for 3D printing” and “3MF vs STL” cover the differences, and “How to read G-code” explains what the slicer produces afterwards.

Are the guides kept up to date?

They are updated in place when a format or a tool changes, rather than being replaced with a new post, so an older publication date does not mean the content is stale.

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