About JiniTools
JiniTools is a free collection of file-conversion and calculation tools that run entirely in your browser. From image compression and PDF conversion to property tax, stock averaging, and payroll-deduction calculators, we gathered the things people actually need every day — without installs, without sign-up, and without any cost beyond viewing ads.
Core principle: your files never leave your browser.
All file processing happens locally in your browser. Once you close the tab, the data is gone. Even the site operator has no way to access your files.
Why we built this
"I want to compress an image but I'm not sure which random site to trust." "I needed to redact my ID copy and ended up uploading it to a sketchy-looking page." "Just to use one tool I had to sign up and watch a 30-second ad." These were the experiences that started JiniTools. The tools people need every day weren't well organized in a form that was both simple and safe.
So we set four rules. Files never leave the browser (everything runs in-page). No sign-up (we don't collect personal data, so there's nothing to store). No paywalls (no usage caps, file-size limits, resolution downgrades, or watermarks; operating costs are covered by ads only). Prioritize Korean daily-use tools first (because that's the gap we kept hitting — housing subscription points, jeonse-to-monthly-rent conversion, resident number validation, and so on), with English and Japanese parity coming alongside.
Our promises
- 0% upload. No file is sent to our servers or any third party. You can verify this in your browser's DevTools Network tab.
- No sign-up. Every tool works without registration or login. We don't collect personal information.
- No paid tier. No usage counts, file-size limits, resolution caps, or watermarks on free users. Operating costs are covered by ads alone.
- Minimal third-party tracking. Beyond Google AdSense, we run no external analytics or tracking scripts. Our own metrics use Cloudflare Web Analytics, which doesn't use cookies.
- Open libraries only. Every dependency (pdf-lib, PDF.js, JSZip, etc.) is MIT/Apache 2.0 licensed and pinned to an explicit CDN version to prevent silent code injection.
- If we change a promise, we tell you. If any of the above changes, the home page, this page, and the privacy policy will be updated together.
Why JiniTools?
Your files are never sent to a server, keeping your privacy safe.
Use every tool for free without signing up.
Instant, in-browser — no upload or download round-trip.
Works on PC, tablet, and smartphone.
Available tools
Currently we offer 148 tools across 5 categories.
- Image tools — Compress, convert, resize, crop, HEIC→JPG, batch processing, collage, Instagram split, and more
- PDF tools — Merge, split, image/text extraction, page editing, watermark, page numbers
- Privacy — EXIF metadata removal, image redaction/mosaic, watermark, resident number format check
- Text / data — JSON formatter, regex tester, text diff, Markdown↔HTML, jamo normalizer, Korean↔English keyboard layout, and 39 more
- Other (incl. Korea-specific) — Four major insurances, take-home pay, severance, housing subscription points, property acquisition tax, broker fees, jeonse↔monthly rent, stock average price, savings interest, car tax, pregnancy weeks, BMR/calories, child grade/height/GPA, pet age, and ~70 more
Browse the full list on the home page or in the other tools category.
Roadmap
We prioritize tools with high real search demand and a well-defined formula. Upcoming themes:
- Finance & tax expansion: capital gains tax (single-home exemption case first), simplified income tax, government childbirth subsidy guide
- Korean family / relationship tools: family-title/kinship calculator, wedding & 60th-birthday D-day tools
- Student & jobseeker tools: language-exam score conversion, cover-letter character counter, time-sum simulator
- Accessibility & multilingual parity: bring English/Japanese pages to full content parity, screen-reader compatibility audit
- Performance: font and image optimization, target initial load under 200 ms
If there's a tool you'd like, reach us via email or Discord. We reply within a week.
Frequently asked questions
Are files really never uploaded? How can I verify it?
Yes. Open your browser DevTools (F12), switch to the Network tab, then drop a file into any tool. You'll see no upload request. Every tool runs inside the browser using trusted open-source libraries like PDF.js, pdf-lib, and JSZip.
Why is it free? Will it become paid later?
Operating costs (domain + CDN) come to about USD 12/year, which ad revenue easily covers. We don't plan to gate features behind usage limits, file-size caps, or resolution downgrades. If the business model ever changes, we'll announce it on the home page first.
Where do ads appear?
Some pages may show Google AdSense units, placed only in positions that don't cover the working area (top/bottom of pages). Ads never block your output or download buttons. AdSense cookie usage is documented in the privacy policy.
Does every tool work on mobile?
Yes. We test every tool down to a 360 px width. That said, memory-heavy operations (PDF or batch image processing) depend on device specs — mobile devices can typically handle up to ~200 MB, desktops up to ~500 MB.
I got a wrong result from a tool. How do I report it?
Email jini506410@gmail.com or message us on Discord with the tool name, your input, the expected result, and the actual result. Tax and rate tools occasionally lag behind annual law changes — please cross-check with official sources where available.
Can you add a new tool?
Yes, with one constraint: it must work without sending user files outside the browser. Tools that depend on external APIs (e.g. live exchange rates, address lookup) don't fit our core principle and are out of scope. Everything else is prioritized by search demand and implementation complexity.
Who runs this site? Is it a business?
JiniTools is a personal side project. There's no parent company. Ad revenue is reinvested into new tools, hosting, and domain renewals. For collaboration, acquisition, or ad-partnership inquiries, please email us.
Are other languages supported?
We currently support Korean, English, and Japanese. Every tool and category page is translated, and you can switch language instantly with the toggle in the header. Additional languages (Chinese, Vietnamese, etc.) will be considered based on demand.
Technical information
JiniTools is a static website built with the Astro framework. File processing relies on the browser's built-in Canvas API plus open-source libraries under MIT/Apache 2.0 (pdf-lib, PDF.js, JSZip, and more).
The site is hosted on Cloudflare Pages with no backend server. All tool logic is JavaScript running in your browser — you can view the page source to see exactly which libraries and code execute.
Contact / feedback
Feature suggestions, bug reports, collaboration proposals — anything is welcome. We typically reply within 1–3 business days.