Pico - a Tiny Browser

A tiny, neumorphic Windows browser for local development — and, since 0.32, a download manager. One portable Pico.exe: no installer, no embedded manifest, static CRT. Pico auto-detects the dev servers already running on your machine, serves local files with live reload, and stays out of the way the rest of the time.

Download

Grab Pico.exe from the Releases page and run it. It needs the Microsoft Edge WebView2 Runtime, which ships with Windows 11 and recent Windows 10.

• Size: 1,639,936 bytes
• SHA-256: 805d9c4e2a87792d11fd99662f3d0c640bb2dc1af5ae3c33bd876764d95342e4

Everything Pico keeps — settings, the log, the cached filter lists and the WebView2 profile — lives in a data\ folder beside the exe, so Pico is fully portable: copy the folder anywhere and it works the same. Download state lives there too (data\downloads\); finished files land in a Downloads folder beside the exe when it is writable (otherwise your Windows Downloads folder).

Screenshots

The start page: running dev servers as cards, what the Shield and Lite have saved, and live downloads at a glance.

The download manager: every file with its progress, live speed, and controls; finished files carry a SHA-256.

What's inside

• Tabs and navigation — the usual browser basics, nothing else: no bookmarks, no history page, no accounts, no sync, no telemetry, no extensions, no settings page.
• A real download manager — downloads are handled by Pico itself, not handed to the browser engine: multi-connection HTTP(S) downloads with ranged segments that split and rebalance as they go, pause and resume (across restarts, too), 1–5 downloads at a time with a per-download connection count and an optional overall speed limit. Clicks that start a download confirm with a toast; failures say why and retry on their own with backoff.
• A downloads popover and page — the toolbar button opens a compact card: every active download with its progress bar, live speed and time left, plus pause / resume / cancel. The full page (pico://downloads, or Ctrl+J) holds the whole history with search and status filters, per-file actions, a SHA-256 for every finished file, and Refresh link for the download whose signed link has expired — Pico re-reads a fresh link from the page you got it from instead of starting over.
• Pico's own right-click menu — links, images and selections get a small menu in Pico's style (the browser's built-in menu is off): open in a new tab, copy link / image / selection, save image, paste, select all.
• The Shield — a three-layer ad and tracker blocker (network rules, cosmetic hiding, scriptlets) running the real EasyList, EasyPrivacy and uBlock filter lists with Adblock-Plus semantics. The lists are not bundled: on first run Pico downloads them from their canonical sources (see SOURCES.md) and caches them in data\lists\. A main-frame page is never blocked, loopback is never blocked, and the Shield fails open — if the lists are missing or the engine is unsure, the page loads.
• Lite mode — an aggressive page diet for heavy sites, with chosen-video semantics: exactly one video per page may play (the one you chose); previews and background videos stay dead.
• A start page that finds your servers — running localhost services appear as cards, with a savings band showing what the Shield and Lite have blocked and saved (bandwidth and time figures are estimates, marked as estimates).
• Sixteen themes — palette themes in light and dark that recolor everything live, including the start page and the downloads page while they are open.
• Local files done right — drag an .html file in (or open one) and it is served from a loopback-only local server with live reload when the file changes.

Troubleshooting

• A download failed with 403 / an expired link — open the downloads page and use Refresh link on that row; Pico revisits the page the download came from and picks up the fresh link, keeping your progress where the server allows it.
• The Shield seems off on first run — the filter lists download once, in the background; on a slow connection the first run may browse unfiltered for a minute. pico.log (in data\) says shield: lists compiled when they land.
• A site looks broken — turn the Shield or Lite off for a moment (toolbar toggles); both fail open by design, and Pico keeps no other content policies.

Security

SECURITY.md describes the design: how downloads are captured and routed, how cookies are scoped per task and never logged, how file names are made safe, the host wall on the local server, what the log redacts, and the 0.40.1 audit pass and the 0.40.2 external-review fixes. In short: Pico stores no passwords, sends nothing anywhere except the requests your browsing makes and the one-time filter-list download, and its internal pages cannot be opened or driven by web content.

Building from source

You need Rust and the Windows target tooling (cargo-xwin with LLVM). Then:

cargo xwin build --release --target x86_64-pc-windows-msvc
python scripts/check_no_manifest.py target/x86_64-pc-windows-msvc/release/Pico.exe

The gate script proves the shipped binary carries no embedded manifest (zero RT_MANIFEST entries), only the icon resource, and no CRT imports — Pico's hard laws, checked on the final artifact. The test battery is scripts/battery.sh (Rust suites plus a DOM suite that drives the real pages in jsdom).

Notes

• Language: Rust only (tao / wry / WebView2).
• Filter lists are downloaded, never bundled; their licenses stay with them (SOURCES.md).
• Rendering: Microsoft Edge WebView2.
• Find the author on Telegram (https://t.me/iK4w4) and YouTube (https://www.youtube.com/@iK4w4).

License

MIT — see LICENSE. Copyright (c) 2026 iK4w4.