Guides

Practical write-ups on doing common file, image and document jobs without handing your data to a third party.

Every tool on this site runs in your browser — no upload, no account, no retained copy. These guides explain the reasoning behind that choice and walk through the jobs where it matters most: costing an LLM integration, shipping a drawing to a client, cleaning up product photos, and removing sensitive text from a PDF before it leaves your hands.

LLM API Pricing Compared: What 1M Tokens Really Costs

A practical comparison of OpenAI, Anthropic, Google and DeepSeek API pricing per million tokens, with worked examples of what a real chatbot, summariser and batch job actually cost per month.

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How to Convert DXF to PDF Without Uploading Your Drawing

A step-by-step guide to turning AutoCAD DXF files into shareable PDFs entirely offline — why drawing files are a confidentiality risk on upload-based converters, and how to check the output before sending it out.

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Offline Background Removal: Why Local Beats Free APIs on Privacy

How browser-based background removal works with WebAssembly and ONNX models, why it keeps product photos and ID images off third-party servers, and when a local model genuinely beats a cloud API.

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How to Redact a PDF Properly Before You Share It

Why drawing a black box over sensitive text is not redaction, how PDF metadata and hidden layers leak information, and a practical checklist for cleaning a document before it leaves your hands.

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Why we write about not uploading

Most "free online tool" sites are free because the upload itself is the product: the file, the usage data, or both. That trade is fine for a holiday photo and unacceptable for a contract, a drawing, a medical image or a customer list. Every guide here is written from the position that the safest place for your file is your own machine, and that a tool which never receives it cannot leak it.

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