Guides
Clear, practical explainers for the tasks our tools help with — no jargon, real examples, and a link to the right tool at the end of each one.
How to Merge PDF Files Online for Free
Why merging beats sending separate attachments, how PDF merging works, and a step-by-step workflow for combining files without losing quality.
How to Split a PDF into Separate Files
The difference between extracting page ranges and splitting every page apart, how to write a page range, and what stays unchanged.
How to Rotate Pages in a PDF
Why viewer rotation doesn't stick, how to permanently fix a sideways or upside-down PDF, and what to do when only some pages are affected.
How to Reorder or Delete PDF Pages (Organize PDF)
When to reorder or delete pages instead of splitting or merging, and how to do it with a drag-and-drop thumbnail workflow.
How to Crop a PDF's Margins or Page Area
How PDF cropping works, the difference between cropping and resizing, and how to trim margins or isolate part of a page.
How to Add a Watermark to a PDF
Text vs. image watermarks, how to get the opacity and position right, and a step-by-step workflow for stamping a PDF.
How to Add Page Numbers to a PDF
How to number PDF pages that don't have them, using the {n}/{total} format template and a custom starting number.
How to Convert JPG Images to PDF
How to combine photos or scans into a single PDF, choose the right page size and orientation, and keep full image quality.
How to Convert PDF Pages to JPG Images
How to turn PDF pages into JPG images, the difference between resolution and quality settings, and when this is (and isn't) the right tool.
How to Compress a PDF File (and What Actually Shrinks It)
Why PDFs get large, the difference between structural bloat and heavy images, and how to pick the right compression mode for each.
How to Sign a PDF Online
How to add your own signature to a PDF by drawing or typing it, what a visual signature does and doesn't guarantee, and when you need more than that.
How to Edit Text and Add Annotations to a PDF
Why most PDF editing is really markup on top of the page, what you can add, and a simple workflow for annotating a document quickly.
How to Redact a PDF Properly (Why Covering Text Isn't Enough)
Why drawing a black box over PDF text doesn't remove it, and what a correct, flatten-and-rebuild redaction process actually requires.
How to Repair a Corrupted or Damaged PDF
Why PDFs sometimes stop opening, how a lenient-parser-and-rebuild recovery approach works, and what it can and can't fix.
How to Scan Documents to PDF With Your Phone or Webcam
How to turn paper documents into a PDF using your device's camera, tips for a clean capture, and the fallback photo-upload workflow.
How to Fill Out a PDF Form Online
How fillable PDF forms (AcroForms) work, how to fill one out and flatten it, and what to do when a PDF has no fillable fields at all.
How to Compare Two PDF Files for Differences
How text-based PDF comparison works, how to read an inline word diff, and where a text-only comparison falls short of a visual diff.
What Is PDF/A and How to Prepare a PDF for Archiving
What the PDF/A archival standard requires, why it differs from a regular PDF, and how to give a PDF clean, honest archival-style metadata.
How to Convert a PDF to Word (and What to Expect)
How PDF-to-Word conversion actually works, what gets preserved, and how to get a clean, editable .docx from your PDF.
How to Convert a PDF to PowerPoint Slides
Why PDF-to-PowerPoint conversion uses full-slide images for visual accuracy, and when that approach is the right one.
How to Convert a PDF to an Excel Spreadsheet
Why PDFs don't actually contain tables, how position-based row/column reconstruction works, and how to check the result.
How to Convert a Word Document to PDF
How Word-to-PDF conversion works in the browser, what to double-check afterward, and when to use it over printing to PDF.
How to Convert a PowerPoint Presentation to PDF
Why PowerPoint-to-PDF is one of the hardest browser-based conversions, what this tool actually extracts, and when to use PowerPoint's own export instead.
How to Convert an Excel Spreadsheet to PDF
How to turn a spreadsheet into a clean, shareable PDF, including tips for wide sheets, hidden columns, and multi-sheet workbooks.
How OCR Works: Making Scanned PDFs Searchable
What optical character recognition actually does, why it's slower than other conversions, and how to get the most accurate result.
How to Convert a PDF to Markdown for Notes and LLMs
How heading, list, and table detection works when converting a PDF to Markdown, and why Markdown is a better LLM input than raw text.
How to Compress Any File Into a Smaller ZIP
How ZIP compression actually works, which file types shrink the most, and when zipping is useful even if the size barely changes.
What Is a UUID? A Practical Guide for Developers
What UUIDs are, why version 4 is the one you'll use, when to prefer them over sequential IDs, and the security misconception to avoid.
URL Encoding Explained (Why You See %20 in Links)
What percent-encoding is, how it works, and the difference between encoding a whole URL and a single parameter value.
How to Write Title Tags and Meta Descriptions
How to write title tags and meta descriptions that rank and get clicks — ideal lengths, what to include, and why Google sometimes rewrites them.
Understanding JWTs: What's Inside a JSON Web Token
The three parts of a JWT, how to read the claims, and the critical point that a JWT is signed — not encrypted.
How to Compress Images for the Web (Without Losing Quality)
How image compression works, resizing vs. quality, choosing JPEG/WebP/PNG, and a simple workflow to shrink images without visible loss.
Regular Expressions: A Beginner's Guide
Learn regex from scratch — the core building blocks, flags, capture groups, and the one performance trap to avoid.
How to Format JSON: Beautify, Validate, and Minify
A practical guide to reading and cleaning up JSON — pretty-printing, catching syntax errors, and minifying for production.
What Is Base64 Encoding? A Plain-English Guide
What Base64 is, why it exists, where you'll run into it, and why it is not encryption — explained without the jargon.
Unix Timestamps Explained (and How to Convert Them)
What a Unix timestamp is, the seconds-vs-milliseconds trap, time zones, and how to convert to and from human dates.
Converting Between CSV and JSON: A Practical Guide
How CSV and JSON differ, when to use each, and how to convert cleanly in both directions without corrupting your data.
How to Create a Strong Password (2026 Guide)
What actually makes a password strong, why length beats complexity, and how to manage unique passwords without losing your mind.
HEX, RGB, and HSL: Web Color Codes Explained
The three color formats you'll meet in CSS, what each number means, when to use which, and how to convert between them.