JSON fundamentals
Syntax, errors, validation, paths, schemas, APIs, and large files.
11 guidesBacodev learning center
Professional guides for data, code, and documents
Detailed references, working examples, and repeatable workflows connected directly to the tools that complete each task.
Browse by topic
Browse by topic
CSV and databases
Cleaning, duplicate removal, reliable interchange, and SQL generation.
4 guidesDeveloper and API security
Regular expressions, JWT inspection, HTTP headers, and API workflows.
3 guidesMarkdown and documents
Portable authoring, email HTML, publishing, and syntax reference.
3 guidesPrivacy and text quality
Local processing, Unicode awareness, and controlled text cleanup.
2 guidesFormat references
Technical reference pages for JSON, CSV, Markdown, and YAML.
4 referencesPDF and documents
Email size limits, private merging, page export, compression, and local PDF workflows.
8 guidesImages for the web
PNG to JPG conversion and size reduction without visible quality loss.
2 guidesQR codes
Guest Wi-Fi codes and branded QR codes that still scan reliably.
2 guidesCalculators and finance
Mortgage payments, BMI, and fair tip splitting with instant local math.
3 guidesExplore all guides
Explore all guides
Use practical documentation for formatting, repair, validation, conversion, security review, publishing, and data cleanup. Every guide connects explanation to a working tool.
How to format and validate JSON correctly
Learn a reliable workflow for making JSON readable while confirming that the document remains valid strict JSON.
Learn moreCommon JSON syntax errors and how to fix them
Most invalid JSON comes from a small set of strict syntax rules. This guide shows how to identify each problem, why a parser rejects it, and how to produce a valid replacement without changing the intended data.
Learn moreHow to repair invalid JSON without hiding data changes
Repair common JSON problems while preserving an auditable view of every automatic change.
Learn moreHow to fix escaped JSON strings and nested JSON text
Recognize JSON stored inside a string, remove one correct escape layer, and avoid damaging valid backslashes.
Learn moreHow to work with large JSON files without freezing the browser
Process large JSON more safely by limiting rendering, using workers, sampling arrays, and choosing the correct conversion workflow.
Learn moreHow to inspect a JSON API response before integration
Review response structure, field types, nullability, record consistency, size, and sensitive fields before writing integration code.
Learn moreHow to compare two JSON API responses
A reliable API comparison should show the exact data path, classify each change, and separate structural compatibility issues from ordinary value changes.
Learn moreHow to validate JSON with JSON Schema
Use JSON Schema to check required fields, data types, arrays, enumerations, and nested response contracts.
Learn moreJSONPath query guide with practical examples
Learn how to select properties, array records, recursive fields, slices, unions, and filtered values from JSON.
Learn moreHow to convert nested JSON to CSV
CSV stores rows and columns, while JSON can contain nested objects, arrays, and mixed structures. A reliable conversion requires clear rules for selecting records, naming columns, and representing nested values.
Learn moreHow to clean CSV data without losing important values
Use a controlled cleanup sequence for delimiters, headers, blank rows, whitespace, duplicates, dates, and inconsistent values.
Learn moreHow to remove duplicate CSV rows safely
Define a reliable duplicate key, normalize comparable fields, choose which record to keep, and preserve an audit trail.
Learn moreHow to convert CSV data into safe SQL inserts
Map CSV columns to database fields, infer types cautiously, escape values, handle nulls, and test generated statements inside a transaction.
Learn moreHow to test regular expressions with reliable examples
Turn a text requirement into a testable pattern, understand flags and groups, cover edge cases, and watch for performance problems.
Learn moreHow to inspect a JWT without confusing decoding with verification
Read JWT headers and claims, interpret time fields, identify algorithm warnings, and understand why decoded content is not automatically trusted.
Learn moreHow to review HTTP security headers
Inspect response headers, understand the role of major browser protections, review CORS and caching, and verify the final production response.
Learn moreA professional Markdown publishing workflow
Structure a Markdown source file, control links and assets, preview target-specific output, and export reliable HTML, Word, or PDF documents.
Learn moreHow to convert Markdown into email-safe HTML
Write a clean Markdown source, convert it to conservative HTML, inline essential styles, and test links, images, accessibility, and client rendering.
Learn moreA safe workflow for cleaning text and line-based data
Remove unwanted whitespace, duplicate lines, invisible characters, and inconsistent punctuation while preserving a reviewable original.
Learn moreWhat local browser processing means for online tools
Understand which work happens on your device, what browser storage may retain, where server or AI processing differs, and what limits still apply.
Learn moreJSON syntax and data type reference
Review strict JSON objects, arrays, strings, numbers, booleans, null values, escaping rules, and common differences from JavaScript object literals.
Learn moreCSV format reference for reliable imports and exports
Understand records, fields, delimiters, quoting, embedded line breaks, headers, encoding, line endings, and spreadsheet safety.
Learn moreMarkdown syntax and portability reference
Review headings, paragraphs, emphasis, links, images, lists, blockquotes, code, tables, and common portability concerns.
Learn moreYAML syntax reference for configuration and data files
Understand indentation, mappings, sequences, scalars, quoting, block text, booleans, null values, anchors, and conversion concerns.
Learn moreA practical PDF and image conversion workflow
Convert PDF pages to images and images back to PDF without losing control of quality, size, or privacy.
Learn moreHow to extract text from PDF documents reliably
Extract the text you need from a PDF without retyping it, and understand why some pages yield no text at all.
Learn moreHow to send a large PDF when Gmail blocks the 25 MB attachment limit
Gmail rejects attachments larger than 25 MB, but most oversized PDFs can be shrunk in a minute without uploading them anywhere.
Learn moreHow to combine tax documents securely without uploading them to the cloud
Tax season means merging W-2s, 1099s, receipts, and returns into one file, and doing it without handing those documents to a third-party server.
Learn moreHow to convert a specific PDF page into a high-resolution JPG
Need one chart or one invoice page as an image? Export it properly instead of screenshotting it, and you get a sharper, print-ready JPG.
Learn moreHow to compress a PDF for email without losing important quality
The right compression keeps a PDF under email limits while text stays sharp and images stay presentable. Here is how to hit that balance.
Learn moreHow to merge multiple PDFs on your computer without installing software
Combining PDFs used to mean installing a desktop app or registering for an online service. In a browser, it now takes one page and a few clicks.
Learn moreHow to convert PNG to JPG without uploading your images
PNG is great for graphics but heavy for photos. Converting to JPG shrinks the file dramatically, and it can be done in your browser without uploading anything.
Learn moreHow to reduce image size for a website without visible quality loss
Heavy images are the most common reason pages load slowly. Cutting image weight is usually invisible to visitors and dramatically improves performance.
Learn moreHow to convert images to PDF locally for sharing or printing
A folder of photos becomes one shareable, printable PDF in a minute, and doing it in the browser keeps the images on your device.
Learn moreHow to create a Wi-Fi QR code for guests without an app
A Wi-Fi QR code lets visitors join your network by pointing their camera at it. Generating one takes seconds and needs no app on your phone.
Learn moreHow to generate a QR code with a logo for free
A logo in the middle of a QR code makes it recognizable and trusted. With high error correction and a small overlay, the code still scans reliably.
Learn moreHow to calculate mortgage payments before talking to a lender
Walking into a lender meeting with your own payment estimate changes the conversation. The math is straightforward once you know the inputs.
Learn moreHow to calculate BMI correctly and what the number means
BMI is a quick screening number, but only if the inputs are measured correctly and the result is read with its limitations in mind.
Learn moreHow to calculate a tip and split a bill fairly
End-of-meal math should take seconds, not a phone gallery of awkward calculations. A tip calculator turns the check into a fair share for everyone.
Learn moreHow to convert Word to PDF without losing formatting
Learn what actually breaks when Word files become PDFs and how to keep fonts, page breaks, and hyperlinks intact.
Learn moreHow to password-protect a PDF
A practical walkthrough of locking PDF files with a password in your browser, from choosing passwords to sharing the file safely.
Learn moreHow to split a PDF into pages or ranges
Learn how to divide a PDF into single pages or page ranges with a local browser tool, and how to keep the parts organized.
Learn moreHow to resize images for Etsy, eBay, and Amazon
Learn the listing image requirements for the major marketplaces and how to resize photos to match, locally in your browser.
Learn moreHow to convert Excel to CSV without breaking UTF-8
Learn how to export Excel data to CSV without corrupting accents, symbols, leading zeros, or date formats.
Learn moreHow to convert Markdown to a Word document
Learn how to turn Markdown files into Word documents with the structure intact, so reviewers get clean DOCX output.
Learn moreHow to create strong passwords
Learn how to create passwords that resist cracking: what makes them strong, why length beats complexity, and how to store them.
Learn moreHow to generate and use UUIDs
Learn what UUIDs are, how version 4 random UUIDs work, and when to use them for database keys and API identifiers.
Learn moreHow to format SQL for readability
Learn the formatting rules that make SQL reviewable: clause placement, indentation, casing, and using a formatter consistently.
Learn moreHow to convert JSON to TypeScript safely
Learn how to turn JSON payloads into TypeScript types without losing safety: interfaces, unions, nullability, and keeping types in sync.
Learn moreHow to convert cooking units: grams, cups, and ounces
Learn how to convert cooking measurements between grams, cups, ounces, and milliliters, and why density changes the math.
Learn moreHow to check JWT expiry before using a token
Learn how to read the exp claim in a JWT, check expiry against the current time, and handle tokens that are near expiration.
Learn moreHow to debug CORS errors in the browser
Learn how to diagnose CORS errors step by step: what the browser message means, which headers to check, and how to fix the server.
Learn moreHow to encode and decode Base64, and why it is not encryption
Learn how Base64 works, when to use it for transport, how to encode and decode it locally, and why it is not encryption.
Learn moreHow to make a PDF from images
Learn how to combine JPG, PNG, and WebP images into one PDF locally, with ordering, orientation, and page size controls.
Learn moreHow to number pages in a PDF for reports and contracts
Learn how to add page numbers to a PDF locally, choose position and style, and handle offsets for cover pages.
Learn moreHow to convert HTML to PDF in your browser
Learn how to turn HTML into a PDF with the print engine already built into your browser, without uploading the file anywhere.
Learn moreHow to view and edit PDF metadata safely
PDF files carry hidden metadata: the author, the application that created the file, and timestamps. Learn how to view and edit it locally before sharing documents.
Learn moreHow to convert HEIC to JPG on any device
iPhone photos arrive as HEIC files that many sites and programs cannot open. Learn how to convert them to JPG in the browser on any device.
Learn moreHow to write a README that actually helps
A README is the first page of your project. Learn which sections it needs, how to write for readers who know nothing yet, and how to generate a strong starter.
Learn moreNo guides match your search. Try JSON, CSV, API, regex, Markdown, YAML, or privacy.
What makes a Bacodev guide useful
What makes a Bacodev guide useful
Technically specific
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Built around examples
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Connected to action
Each guide leads to the exact tool required to inspect, test, convert, or export the result.
