Free file tools that run entirely in your browser. Live at tools.dcln.me.

No uploads. No accounts. No ads. No cookies. Open source under MIT.

Most online file tools upload your file to a server, process it there, and offer you the result. The privacy promises are typically "we delete it after an hour" — not "we never had it."

Modern browsers can do this work locally. So that's what these tools do.

All nine product families are live. Each lives at a single URL with operations exposed as tabs — no per-operation URLs.

The canonical catalog lives in src/lib/tools.ts and feeds the homepage, 404 page, and sitemap.

• Astro 6 — multi-page output, islands architecture
• Preact (compat) — interactive widgets (~10 KB instead of React's ~45 KB)
• Tailwind v4 — via the @tailwindcss/vite plugin

Per-area workhorses:

Infrastructure:

• Cloudflare Workers Static Assets — hosting
• Cloudflare R2 at cdn.dcln.me — for WASM blobs that exceed the 25 MiB per-asset cap
• Cloudflare Web Analytics — no cookies, no fingerprinting

Native browser APIs are preferred over libraries wherever possible: crypto.randomUUID, SubtleCrypto, CompressionStream, OffscreenCanvas, createImageBitmap, WebCodecs. Heavy work runs in Web Workers.

Node 22+ required.

npm install
npm run dev           # local dev server at http://localhost:4321
npm run build         # production build → dist/
npm run preview       # serve the production build locally
npm run check         # astro check (type + Astro template diagnostics)
npm run lint          # eslint
npm run test:e2e      # Playwright suite (102 tests)
npm run test:fixtures # rebuild e2e/fixtures/* from source (needs ffmpeg + network)
npm run test:report   # build test-artifacts/index.html — visual before/after viewer

End-to-end tests live in e2e/*.spec.ts and exercise every hub against real fixtures committed under e2e/fixtures/ — small but authentic files (Big Buck Bunny clip @ CC-BY 3.0, real DOCX, multi-page PDF with embedded images, JPEG with real EXIF tags, ZIP/TAR/TAR.GZ archives, etc.).

Fixtures are produced deterministically by scripts/build-fixtures.mjs; regenerate with npm run test:fixtures. Provenance and licenses are documented in e2e/fixtures/README.md.

The Playwright config retries failed tests once locally (twice on CI) to absorb the occasional WebCodecs race under parallel load. The Audio/Video real-fixture suite runs in serial mode for the same reason.

Deploys automatically to Cloudflare Workers Static Assets via Workers Builds on push to main. Manual deploy:

npm run build
npx wrangler deploy

wrangler.toml configures the asset directory and the not_found_handling strategy.

Modes share a hub (PdfHub.tsx, ImageHub.tsx, …). To add one:

1. Library at src/lib/<area>/<op>.ts — framework-agnostic, unit-testable.
2. Worker at src/lib/<area>/<op>.worker.ts if the work is heavier than ~50 ms — wraps the lib in a postMessage interface.
3. Panel at src/components/tools/<PanelName>.tsx — Preact, manages its own state. Use the shared widgets:
   • FileDropZone for input
   • OutputPanel for text outputs with copy/download
   • Unified Status discriminated union (idle | loading | working | done | error)
   • Fieldset + Pills for option groups
4. Register in hub — add a Mode literal and a ModeSpec blurb to the hub component, plus a conditional render block. Use the generic Hub wrapper.
5. E2E — extend the relevant e2e/<hub>.spec.ts with a tab-click + real-fixture round-trip test.

1. Catalog entry in src/lib/tools.ts — slug, name, blurbs. This drives the homepage, 404, and sitemap automatically.

2. Hub at src/components/tools/<Family>Hub.tsx modelled on an existing hub.

3. Page at src/pages/<family>.astro — uses HubPageLayout which assembles the visible markup + HowTo + FAQPage + BreadcrumbList JSON-LD from a single data block.

4. E2E at e2e/<family>.spec.ts — add a real-fixture spec block. If the new family needs new fixture types, extend scripts/build-fixtures.mjs and e2e/fixtures.ts.

5. WASM > 1 MB — upload to R2 at cdn.dcln.me/<lib-name>/<version>/<file> and load from there. Pin the version.

   wrangler r2 object put dcln-assets/libheif/1.19.8/libheif.wasm --file=./libheif.wasm

• Lighthouse ≥95 across Performance, Accessibility, Best Practices, SEO. Release blocker.
• Drag-and-drop must have a keyboard-accessible fallback (visible click-to-select button, arrow buttons for reordering).
• ARIA live region for progress and completion.
• "Files never leave your browser" copy visible above the fold.
• No third-party scripts beyond Cloudflare Web Analytics. No cookie banner.

This project uses Conventional Commits. Every commit and PR title must follow the pattern:

type(optional-scope): short description

Types: feat, fix, docs, style, refactor, perf, ci, chore, test, build, revert.

For new modes, use the family slug as the scope:

feat(image): add SVG → raster mode
fix(pdf): handle password-protected PDFs gracefully
ci: bump lighthouse threshold to error-level 0.95

commitlint validates commits on every PR via the Commit Messages job in .github/workflows/ci.yml. Past commits made before this convention was added are not retroactively validated.

MIT. See LICENSE.

Test fixtures under e2e/fixtures/ include video frames derived from Blender Foundation's Big Buck Bunny (CC-BY 3.0); see the fixtures README for full per-file provenance.