Rack Label Maker

Free, browser-based label maker for 19" racks, patch panels, and broadcast/AV/pro-audio equipment.

👉 Use it now: labels.rschmidt.dk (no account, no install, nothing uploaded)

Type straight into the label cells, press Tab to move on, and export a vector PDF that prints at true physical size. Everything runs in your browser; there is no backend, account, database, analytics, or cloud storage.

Features

• True-size strips in millimeters, with presets such as a full-rack 432 mm × 16-cell strip and custom widths, heights, and cell counts
• One to three rows per strip and group headers over a range of cells
• Auto numbering with a {n} template (for example CAM {n} or CH {n}) applied only to the selected range
• Automatic sheet layout. Full-width 432 mm rack strips are placed diagonally when needed, so several fit whole on one A3 sheet without gluing. Strips are never scaled
• Vector PDF export and Print for A4, A3, SRA3, US Letter, US Legal, and US Tabloid, with shared cut lines between touching strips
• Split printing with glue tabs when a strip is longer than the paper
• Calibration PDF with an exact 100 × 100 mm square to check your printer
• Project files (.racklabel) you can save, share, and reopen
• Installable and offline-capable as a PWA

Click Example in the toolbar to load a filled-in OB truck rack and see it in Page layout preview:

Support the project

Rack Label Maker is free and will stay free. If it saved you an afternoon of fiddling with spreadsheets and label printers, you can ☕ buy me a coffee. Starring the repository and sharing the tool with colleagues also helps.

Found a bug or have an idea? Use Send feedback in the app footer or open an issue.

Development

Install dependencies and start Vite:

npm install
npm run dev

Run the automated dimensional and domain tests:

npm test

Run ESLint:

npm run lint

Production build

npm ci
npm run build

The deployable static output is dist/. It contains browser assets only; Node.js is not required after the build. Upload the contents of dist/ to any static host, including:

• Vercel
• Netlify
• conventional static web hosting
• nginx or Apache
• similar static hosting and object-storage/CDN services

Before deployment, serve dist/ with any plain static file server and verify the editor, project Save/Open, lazy-loaded PDF export, Print, and Help/About workflows.

The production build also generates manifest.webmanifest, install icons, registerSW.js, and sw.js. The service worker precaches the application shell for basic offline startup; it does not implement background project sync or an aggressive runtime cache. Run npm run verify:pwa after npm run build to verify the generated manifest, icons, file association, and service worker.

Security headers

vercel.json configures the production CSP and related headers on Vercel. public/_headers is copied to dist/_headers for Netlify-compatible hosts. The policy permits only same-origin application code, local/data images and fonts, and Blob URLs needed by generated PDF/Print workflows; framing and plugin objects are blocked.

For nginx or Apache, configure the equivalent response headers on every static asset and the SPA fallback response:

Content-Security-Policy: default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data: blob:; font-src 'self' data:; connect-src 'self'; worker-src 'self' blob:; object-src 'none'; base-uri 'self'; frame-ancestors 'none'; form-action 'none'
X-Content-Type-Options: nosniff
Referrer-Policy: strict-origin-when-cross-origin
Permissions-Policy: camera=(), microphone=(), geolocation=(), payment=(), usb=()
X-Frame-Options: DENY

Inline styles remain permitted because React uses inline style properties for editor zoom and validated colors. Scripts do not require unsafe-inline or unsafe-eval.

Static SPA fallback

The application currently uses a single screen, but a fallback to index.html prevents future client-side routes or direct navigation from returning a 404.

• vercel.json provides a minimal Vercel rewrite.
• public/_redirects is copied to dist/_redirects for Netlify-compatible hosts.
• On nginx, use try_files $uri $uri/ /index.html; in the site location.
• On Apache, enable mod_rewrite and rewrite non-file/non-directory requests to /index.html.

These files are optional on hosts that already provide a “single-page application” fallback. They do not make the build dependent on Vercel or Netlify.

Custom domain

For a deployment such as labels.rschmidt.dk:

1. Build and deploy dist/ using the chosen static host.
2. Add labels.rschmidt.dk as a custom domain in that host.
3. Create the DNS record requested by the host, normally a CNAME or provider-specific A/AAAA record.
4. Confirm HTTPS is active, then test project Save/Open, PDF export, Print, and PWA installation from the public URL.

No provider credentials, API secrets, or runtime environment variables belong in the repository. The public feedback destination is configured once in src/config/app-info.ts.

Dimensional model

All physical geometry is persisted in millimeters. The strip SVG uses a millimeter-coordinate viewBox and explicit width="…mm" / height="…mm" attributes. Editor zoom and editor-only cell indices never alter or enter physical geometry.

PDF geometry is created directly from millimeters with points = millimeters × 72 / 25.4. No DOM or CSS pixel measurements enter the PDF path. The exporter preserves true strip dimensions, uses deterministic unscaled placement, and draws the exact same print-layout plan shown in Page Preview. Its diagonal heuristic tests multiple angles and staggered offsets, then validates the actual oriented strip polygons. Print settings default to edge-to-edge packing with vector cut lines; a custom gap retains a convenient 2 mm initial value. Layout margins default to 10 mm; SRA3 uses 9 mm left/right margins so the 432 mm rack preset fits horizontally while retaining 10 mm top/bottom margins and the separate print-warning reserve.

Paper, orientation, auto-arrange, spacing, and cut-guide choices are versioned preferences stored locally under a dedicated browser-storage key. Available paper sizes are A4, A3, SRA3 (320 × 450 mm), US Letter, US Legal, and US Tabloid. They are not written into label project files. Existing schema 1–3 projects still open normally. Compatibility schema 4 files containing the former page.stripGapMm field are normalized back to label schema 3; when no valid local print preference exists, that paper configuration and gap seed the initial print settings instead of being discarded. An established local preference always wins.

Export PDF downloads a dated PDF. Print opens the same exact-size PDF in the browser's normal print workflow. Always choose 100% / Actual Size; never choose Fit, Shrink, or Scale to printable area. Some printer drivers silently scale PDFs, so verify the setting manually. The calibration PDF contains a mathematically exact 100 × 100 mm square.

Project files

Save downloads a human-readable, versioned .racklabel document using the project name as its filename, for example FlyAway.racklabel. The custom file is JSON data using the same existing project schema, validation, and migration path; changing the extension does not change or increment the schema version. Older .json project files remain supported by Open and pass through exactly the same reader as .racklabel files.

In a normal browser tab, use Open and Save as usual. Rack Label Maker is also an installable PWA with basic offline application-shell support. On supported Chromium-based desktop browser/OS combinations, the installed app can register as a handler for .racklabel files. Double-clicking an associated document then launches Rack Label Maker and loads the file through the normal project validator without requiring a second Open step.

Native file association is progressive enhancement. It depends on browser, operating-system, installation, secure-origin, and administrator support. A browser without the File Handling or Launch Queue APIs continues to work normally: Open accepts .racklabel and legacy .json, Save downloads a new .racklabel, and PDF workflows are unaffected. Opening a document does not grant or assume permission to overwrite the original file; Save continues to create a download.

Project state is not sent to a backend or cloud service. Print/export preferences are the only current local-storage persistence and remain separate from the project schema.

Numbering

Auto numbering accepts {n} anywhere in either line template; the adjacent # button inserts it automatically. Click a cell to select and edit it, then Shift-click another cell to select a contiguous range. Numbering, clearing, group headers, and cell appearance changes can be applied to the selected range without changing neighboring cells.

New strips begin empty. The neutral Router Out / {n} numbering template is only applied when the user explicitly chooses Apply. Normal label and Print PDFs automatically include the bundled Buy Me a Coffee QR in a collision-safe bottom-right decoration area. It never changes strip placement and never appears in calibration PDFs.

CSV, accounts, printer correction factors, analytics, cloud save, nested headers, and arbitrary uploaded fonts are intentionally not implemented.