Byteflow

Privacy-first developer tools that run in your browser.

120+ formatters, converters, generators, encoders, and workbench utilities for everyday engineering tasks.

Built with Next.js 16, React 19, TypeScript, and Tailwind CSS 4. Static export, no server, no account.

Website · Why Byteflow · Tool Coverage · Quick Start · Development · Privacy · Roadmap · Changelog · Self-hosting · Community Model · Contributing · License · Support

Why Byteflow

Developers often need to inspect JSON, decode JWTs, format SQL, generate UUIDs, convert text, or validate data that should not be pasted into an opaque third-party service. Byteflow is built around a simple operating model: most tool payloads are processed locally in the browser, external-request tools are labeled, and the app ships as a static export.

• Browser-local tool inputs and outputs stay in your browser.
• Tools that need a user-triggered network request are labeled before use.
• No account, upload, workspace, database, or tool-processing API.
• Free to use, self-host, and contribute to under MIT.
• Static hosting friendly through Next.js export.
• Installable PWA; core app shell assets are cached for offline use.
• Seven locales: en, zh-CN, zh-TW, ja, ko, de, and fr.

Tool Coverage

Popular tools include:

• JSON Formatter for formatting, validating, and minifying JSON.
• Base64 Encode/Decode for text and Base64 conversion.
• JWT Decoder for inspecting token headers and payloads.
• Hash Generator for MD5, SHA-256, and SHA-512 hashes.
• URL Encode/Decode for safe URL component conversion.
• UUID Generator for UUID v4 and v7 generation.
• Crontab Generator for building and explaining cron expressions.
• Regex Tester for testing regular expressions.
• JSON to TypeScript for deriving TypeScript types from JSON.

Browse the full catalog at byteflow.tools/en/all-tools.

Quick Start

Use the hosted app at byteflow.tools, or run it locally:

git clone https://github.com/baixiangcpp/byteflow.tools.git
cd byteflow.tools
npm install
npm run dev

Open http://localhost:3000.

Prerequisites:

• Node.js 20.19.0 or newer within Node 20.x
• npm 10.x

The repository includes .nvmrc and package.json engine metadata. Environment variables are optional for local development; see .env.example for the supported keys.

Development

The package is marked private to avoid accidental npm publishes; the source is MIT-licensed and free to self-host. CI gates cover registry generation, i18n, PWA manifests, sitemap data, security headers, static export metadata, and smoke flows.

Command	Purpose
npm run dev	Start the local Next.js dev server.
npm run lint	Run ESLint.
npm run test	Run Vitest unit, component, and guard tests.
npm run check:types	Run TypeScript without emitting files.
npm run validate	Run pre-build gates for service worker, sitemap, security headers, PWA, i18n, generated registry, and types.
npm run build	Run validation, static export build, and post-build route/export checks.
npm run test:e2e:smoke	Run the Playwright smoke test against the built app.
node scripts/e2e/capture-readme-demo.js --start-server	Regenerate the README demo image in public/screenshots/.
npm run create:tool	Scaffold a new tool route, feature module, manifest, and translations.

Generated registry files are checked in because runtime and CI consume them:

npm run generate:tool-index
npm run check:tool-index
npm run generate:client-tool-lookup
npm run check:client-tool-lookup
npm run generate:llms-txt
npm run check:llms-txt

Do not edit files under src/generated/ by hand.

Project Structure

• src/app/[lang]/ contains locale-aware routes and thin tool wrappers.
• src/features/tools/ contains tool-specific feature modules.
• src/core/ contains shared runtime infrastructure, registry, i18n, SEO, storage, and utilities.
• src/generated/ contains checked-in generated registry artifacts.
• scripts/ contains generators, CI gates, post-processing, smoke automation, and scaffolding.
• tests/ contains unit, component, e2e, and structural guard coverage.

Durable architecture references:

• Directory structure
• Module boundaries
• System architecture
• Design system

Adding Tools

Use npm run create:tool when possible, then follow CONTRIBUTING.md for manifests, route wrappers, translations, registry generation, and test expectations.

Privacy and Security

Byteflow's core tools are designed to process payloads in the browser. Tools marked External request disclose when a network lookup is needed. Avoid sharing real secrets, production tokens, private customer data, or sensitive payloads in public issues, screenshots, logs, or reproduction cases.

Report vulnerabilities through the process in SECURITY.md.

Self-hosting guidance is available in docs/deployment/self-hosting.md. The sustainability and support boundary is documented in docs/community-sustainability.md: future team deployment or commercial support must preserve local-first processing, no forced accounts, no cloud history, and no default payload storage.

Contributing

Contributions are welcome when they preserve the local-first privacy model and the guarded architecture boundaries. Start with CONTRIBUTING.md, follow the Code of Conduct, and use the issue templates for bug reports, feature requests, recipe requests, docs requests, or localization fixes.

Roadmap priority uses public signals from GitHub reactions, comments, duplicate issues, severity, privacy risk, and local-first product fit. See docs/community-sustainability.md for the full prioritization method.

Before opening a pull request, run the checks that match your change. For user-facing, registry, i18n, or build-surface changes, run:

npm run lint
npm run test
npm run validate
npm run build

License

Byteflow is released under the MIT License.

Support

• Issues: github.com/baixiangcpp/byteflow.tools/issues
• Security: SECURITY.md
• Changelog: CHANGELOG.md
• Website: byteflow.tools