# Tsudoi

> Tsudoi is a free, open-source, privacy-first visual invitation maker. It edits and exports invitation images entirely in the user's browser.

Canonical site: https://tsudoi.yahaha.net/
Source code: https://github.com/dofy/invite-maker
Support and contact: https://github.com/dofy/invite-maker/issues
Last updated: 2026-08-27

## Product

- [Tsudoi editor](https://tsudoi.yahaha.net/): Upload a background, position and style template text, and export an original-resolution PNG.
- [About Tsudoi](https://tsudoi.yahaha.net/about): Product purpose, architecture, principles, and technical references.
- [Privacy policy](https://tsudoi.yahaha.net/privacy): Local processing, hosting requests, fonts, local preferences, and offline caching.
- [Terms of use](https://tsudoi.yahaha.net/terms): Acceptable use, user content responsibility, availability, and changes.

## Core capabilities

- Visual text layout with dragging, snapping, fixed-width wrapping, alignment, and nine anchor positions.
- TXT data through `{{txt}}`; CSV data through `{{csv.header}}`.
- Dynamic values: `{{date}}`, `{{time}}`, `{{datetime}}`, `{{index}}`, `{{index:N}}`, and `{{uuid}}`.
- Single PNG export at the source image resolution.
- Local batch generation of up to 200 PNG files, packaged as a ZIP.
- Reusable template JSON that excludes the background image and imported recipient data.
- Simplified Chinese, Traditional Chinese, English, German, Japanese, Korean, Spanish, and French interfaces.
- Installable PWA with offline editing and export after the initial load.

## Privacy boundary

Background images, recipient lists, template JSON, canvas state, and generated PNG/ZIP files are processed locally in the browser. Tsudoi has no material-upload endpoint and no server-side image renderer. Static assets are hosted on Cloudflare Pages; optional web fonts are requested from Google Fonts.

## Technical references

- [MDN File API](https://developer.mozilla.org/docs/Web/API/File_API)
- [MDN Canvas API](https://developer.mozilla.org/docs/Web/API/Canvas_API)
- [MDN Service Worker API](https://developer.mozilla.org/docs/Web/API/Service_Worker_API)