Discord message tooling
Build the payload,
see the message.
Lightbook is a builder for Discord embeds, components, Components V2 layouts and modals. Edit on the left, watch a faithful preview on the right, and copy JSON that has already been checked against every limit the API enforces.
Everything runs in your browser. Nothing is uploaded, and your document is kept in local storage between visits.
Embeds→
Title, author, fields, images and footer, with the 6000-character budget counted as you type.
Components→
Buttons and all five select menus, arranged into action rows that respect the five-per-row rule.
Components V2→
Containers, sections, galleries, separators and files — the layout tree behind message flag 1 << 15.
Modals→
Labelled text inputs and selects, rendered as the popup your users will actually see.
What it catches before Discord does
A 400 from the API tells you a payload was invalid. This tells you which field, and why — and clicking the issue takes you to it.
- Character limits on every field, counted live
- Custom IDs required, unique, and within 100 characters
- Rows that mix buttons and selects, or overflow five components
- Containers nested inside containers, and thumbnails outside sections
- Components V2 messages that still carry content or embeds
- The 40-component and 4000-character budgets for V2 layouts
Paste to edit
Drop in an existing payload — a full message, a bare embed, or an array of embeds — and carry on editing it.
Command palette
⌘K reaches every action: jump between builders, add a component at any depth, copy the payload, undo.
Share a link
The document is encoded into the URL fragment, so a link reproduces your work without a server ever seeing it.