Every developer has done this: pasted a JSON payload, a JWT or a chunk of config into a random online formatter and then wondered, where did that just go?
For most free online tools, there's no clear answer. Your input might be processed on a server, logged, or stored. For simple jobs like formatting text or crunching a few numbers, that's a strange thing to have to trust a stranger with.
That question is why I built Tooltri.
What is Tooltri?
Tooltri is a free collection of 30+ browser-based tools for finance, development, writing and everyday tasks. The rule behind every tool is the same:
Inputs are processed in your browser. Nothing is uploaded to a server.
There's no sign-up, and calculator inputs and preferences are saved only in your own browser's local storage, so a refresh doesn't wipe your work.
What's in it
Developer tools
- JSON Formatter: beautify, validate and minify
- JWT Encoder/Decoder
- Base64 Encoder/Decoder
- UUID Generator and Hash Generator
- URL Encoder/Decoder
- SVG to React JSX
- SQLite DB Viewer: open
.dbfiles without uploading them anywhere - Unix Time Converter
Text and AI
- Token Counter: token counts for GPT, Claude, Gemini, Llama and DeepSeek models, with context window usage shown
- ChatGPT Text Cleaner: removes hidden characters and formatting leftovers from AI-generated text
- Word Counter, Text Case Converter and Duplicate Word Finder
Finance calculators (with India-focused ones)
- SIP, SWP, Home Loan EMI and ROI
- Income Tax Calculator (new vs old regime) and In-Hand Salary Calculator
- Profit Margin and CPM Calculator
Files and creators
- Image Compressor, Merge PDF and JPG to PDF, all client-side
- QR Code Generator, Color Converter and YouTube Thumbnail Downloader
Why local-first?
Running everything in the browser has real trade-offs, and I think they're worth it for this kind of tool.
Pros
- Your data stays on your device, which matters for tokens, payloads and financial numbers.
- Results are instant, with no round trip to a server.
- Hosting stays cheap, which is how a free tool stays free.
Cons
- Heavy processing is limited by the user's device.
- Some features that genuinely need a server (for example, fetching remote data) are harder to offer.
For utilities like these, I think the privacy benefit outweighs the limits.
The stack
I work mostly with Next.js, React and Node, and Tooltri is built on that. [Add 2–3 sentences about something you found interesting or difficult: for example, how you count tokens across different model families, how you handle large files in the browser, or how you keep bundle size down.]
What I'd love feedback on
- Which tool did you expect to find and didn't?
- Is there a tool where the output isn't what you'd expect?
- What would make you use it instead of whatever you use now?
Tooltri is still growing, and the roadmap comes mostly from people telling me what's missing.
Try it: tooltri.com
If you'd rather email than comment, there's a contact page on the site.
