Guides

All our guides in English, with a short summary of each.

Best PDF to Markdown tools (2026 comparison)Comparison of PDF to Markdown converters for LLMs and RAG: Marker, Docling, MarkItDown, PyMuPDF4LLM, browser tools and APIs. Licenses, OCR, tables, speed.How to convert PDF to Markdown for LLMsStep-by-step guide to converting PDFs into LLM-ready Markdown: extraction, cleanup, chunking, scanned pages and tables.How to give a PDF to ChatGPTThree ways to give a PDF to ChatGPT: upload, paste text, or paste Markdown. When each works best, how to handle long and scanned PDFs, and a prompt template.Markdown vs plain text for RAGWhy Markdown usually beats plain text for retrieval-augmented generation: structure-aware chunking, heading metadata, tables. With a simple chunking recipe.How to improve OCR accuracyPractical ways to get better OCR results from images and scans: resolution, cropping, contrast, language models, page segmentation modes and checking confidence.Free PDF to Markdown converters comparedFree ways to convert PDF to Markdown in 2026: in-browser converters, open-source libraries (Docling, MarkItDown, Marker) and APIs. Privacy, limits and quality compared.How to merge PDF files into oneCombine several PDFs into one document in the order you want, in your browser. Step-by-step instructions, what is kept and what is not, and common fixes.How to compress an imageShrink a JPG or WebP photo for email, forms and websites: the right quality and width settings, how to hit a size limit like 200 KB, and what to check.How to convert a PDF to JPGTurn each page of a PDF into a JPG image in your browser. Which resolution to pick, how multi-page files are delivered, and what to do when you need text.How to make a QR codeCreate a QR code for a URL, text or Wi-Fi network, download it as PNG or SVG, and make sure it scans. Size, error correction and printing tips.How to extract text from a scanned PDFGet the text out of a scanned or image-only PDF with OCR in your browser. How to tell if a PDF is scanned, language choice, accuracy tips and limits.How to convert Excel to JSONTurn an Excel or CSV file into JSON with one object per row. How headers become keys, what happens with several sheets, empty cells and dates.Website to Markdown API for RAG and LLMsTurn many web pages into clean Markdown with one API call. Polite crawler with robots.txt, sitemap and depth control. Pay per page, no monthly fee.Google Play reviews API and exportExport Google Play app reviews by app, country and language with a simple API. Filter by stars and date, includes developer replies. $0.0004 per review.PDF to Markdown API for bulk conversionConvert hundreds of PDFs to Markdown by API, with table detection and automatic OCR for scanned pages. Pay per PDF, no monthly fee.How to calculate percentage increase and decreaseSimple formulas for percentage change, X% of a number, discounts and VAT, with worked examples and the common mistakes to avoid.SHA-256 vs SHA-1 vs MD5MD5, SHA-1 and SHA-256 compared: digest length, what is broken, what each is still fine for, and why none of them should store passwords.YAML vs JSONYAML and JSON compared: syntax, comments, data types, the "Norway problem", security of YAML loaders, and which format to pick for configs, APIs and data exchange.How to decode a JWTWhat is inside a JSON Web Token, how to decode the header and payload, what iat, exp, nbf, sub, iss and aud mean, and why a decoded token still has to be verified.How to convert a PDF to textExtract the text from a PDF and save it as .txt in your browser: lines rejoined into paragraphs, broken words fixed, and what to do if the PDF is a scan.