Local tools. Local AI.
Nothing else.
The tools you reach for every day,
all bundled in one app,
fully offline.
9 tools
JSON
Format, validate, and explore JSON as a collapsible tree.
Type it.
Find any tool.
Hash
SHA-2, SHA-3, MD5, and SHA-1 digests of text or a file.
UUID
JWT
Base64
Encode and decode text or files.
Cron
Build a schedule, field by field.
Image to Text
Pull text from a screenshot or scan.
Merge, extract, or pull out text.
Images
Convert, resize, and compress.
Every tool, one search away
Press ⌘K from anywhere in Umbra. Format a JSON payload, decode a JWT, build a cron schedule — the same shortcut, every time, without breaking flow to open a new tool.
Verify it yourself
There's no server for your data to go to — with one disclosed exception, an automatic check for app updates. Umbra is a native app, not a client talking to a backend. What you paste, drop, or type is processed on the machine in front of you, by code running on that machine — there’s nothing to intercept, because there’s nowhere for it to go, except for that one exception: once, at launch, Umbra checks GitHub for a newer release, the single network call it ever makes, and nothing installs without you confirming it first.
It’s built this way structurally, not by policy: a native Rust application, compiled to a single binary, with no client-server architecture underneath it for anything to route through in the first place.
The source is public — read it yourself. Umbra's repository is source-available: open the networking layer and confirm this isn't just asserted. (Source-available isn't open source — you can view the code, not redistribute or reuse it. More on that in the FAQ.)
The macOS build is signed with a Developer ID certificate and notarized by Apple, so it opens with no Gatekeeper warning on a clean install.
Don't take our word for it. Quit and relaunch Umbra while this is running, on your own downloaded copy:
nettop -p $(pgrep -x umbra)You'll see one connection — the update check, at launch — and nothing else, no matter which tool you use. (macOS only. Windows and Linux instructions aren't written yet.)
Why Umbra
- Instant. A native Rust app, not a browser tab — cold launch measured under 2 seconds, and kept there as new tools are added.
- However you work. Full keyboard navigation and screen-reader-labeled controls, in every tool.
- Always your call. Every update is a confirmation, not a background install. Nothing changes without you saying so.
- No strings attached. Download and use it — no sign-up, no trial clock, no plan to pick.
Available for macOS, Windows, and Linux.