Do I need to register or pay?

No. Every tool is free, needs no account and has no usage limit; the site is funded by advertising.

Is my data uploaded or stored?

No. Encoding, encryption, hashing and image processing all run inside your browser — inputs and files are never uploaded. You can disconnect your network and keep using the tools to verify this yourself.

Can I use the tools for commercial work?

Yes. Use them freely on your own data; just do not redistribute the site or its code as part of a commercial product.

Are the results guaranteed to be correct?

The tools implement published standard algorithms, but results should still be reviewed — especially for encryption, hashing and format conversion. Back up important data first.

Yyago — Developer Tools & Knowledge Base

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Whiteboard

Sketch-style online whiteboard with PNG / SVG export — data never leaves your device.

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Developer Toolbox

Everyday dev tools: Base64, URL, encryption, Cron and more

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IP Address Lookup

Look up public IP, geolocation, ISP and more

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OCR Text Recognition

PP-OCRv6 image-to-text, supports Chinese & English, runs locally

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Knowledge Base

Original articles by topic: encryption & security, encoding & formats, network & ops, practice

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All Tools

Base64 Encoder/DecoderEncoding URL Encoder/DecoderEncoding Symmetric EncryptionEncoding Asymmetric EncryptionEncoding HashingEncoding JSON FormatterFormatting Cron ExpressionTime Image WatermarkImage Timestamp ConverterTime UUID GeneratorGenerators Password GeneratorGenerators File HashEncoding Base ConverterCalculators Color ConverterCalculators

Knowledge Base

Original articles organised by topic — the principles, the practical steps, and the tools that pair with them.

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AI & Engineering Encryption & Security Encoding & Formats Network & Ops Engineering Practice

AI & EngineeringWhat Is Jev: An AI Decision Model That Does Not Write2026-09-25 · 11 min read AI & EngineeringLocal LLM vs Cloud API: Privacy, Cost and Capability Trade-offs2026-09-24 · 6 min read AI & EngineeringRAG and Context Windows: Show the Model Only What It Needs2026-09-24 · 6 min read

About this site

This is a free online tool site for developers and everyday users. It offers a growing set of browser-based tools — encoding, encryption, formatting and drawing — plus original articles organised by topic, updated regularly. All computation happens on your own device — the plaintext you type and the files you upload never reach our servers.

We hold to three rules: no user accounts, no collection of tool input, and no pop-ups or redirect ads. Every tool page documents its usage, common questions and security boundaries so you know the limits before you rely on it.

Content is updated weekly. If something looks wrong, tell us via the feedback page or email.

Frequently asked questions

Do I need to register or pay?: No. Every tool is free, needs no account and has no usage limit; the site is funded by advertising.
Is my data uploaded or stored?: No. Encoding, encryption, hashing and image processing all run inside your browser — inputs and files are never uploaded. You can disconnect your network and keep using the tools to verify this yourself.
Can I use the tools for commercial work?: Yes. Use them freely on your own data; just do not redistribute the site or its code as part of a commercial product.
Are the results guaranteed to be correct?: The tools implement published standard algorithms, but results should still be reviewed — especially for encryption, hashing and format conversion. Back up important data first.