Your data stays in your browser
Your developer toolkit, simplified.
Fast tools for JSON, JWT, time zones, UUIDs, code formatting and AI prompts. No signup. No uploads. No unnecessary tracking.
See it work
Four of the tools, running on real input right here.
minified.json
84 B, one line
formatted
- Valid JSON
- 10 lines
- 2-space indent
Real output, computed in this page by the same code the tool runs.
Open JSON FormatterPopular tools
The tools most people come for.
Browse by category
Every tool, grouped by what it works on.
Why ToolJar
Works offline
Once a page has loaded, its tool keeps working without a connection.
Free, without limits
No subscriptions, no paywall and no usage caps. Open a tool and use it.
Exact errors
Errors name the line and column that broke, and results update as you type.
Frequently asked questions
Is it safe to paste production data or a real token?
Nothing you paste leaves your browser. There is no server to send it to. You can confirm it in your browser's network panel. A live token pasted anywhere is still worth rotating if it grants real access.
Do the tools work offline?
Yes. Once a page has loaded, its tool keeps working without a connection, because all the processing happens in the page itself. Two things are fetched on first use: the minifier behind Minify in the JavaScript Formatter, and the tokenizer the Token Counter loads once you edit the text.
Is ToolJar free?
Yes. There are no accounts, subscriptions or usage limits.
How can it be free?
ToolJar is a static site with no backend, so it costs almost nothing to run, and nobody is paying for your data. It does count page views, with Cloudflare Web Analytics, which sets no cookie. Cloudflare's bot protection sets one cookie of its own. The privacy page covers both.
Does anything get saved in my browser?
ToolJar stores one thing: whether you chose the light or dark theme. Cloudflare, the host, adds its bot-check cookie. Pasted documents, tokens and secrets live in memory only and disappear when you close the tab. The time and date tools put your input in the page address so a result can be shared, which means it is in your history. Clear that if the link had something sensitive in it.