Just Tool It /
MIME Type Lookup
On-device — nothing uploaded
MIME Type Lookup
Convert between file extensions and MIME types. Type one or many — works both directions.
Why use MIME Type Lookup in your browser?
Developer paste bins often contain tokens, configs, and customer data. MIME Type Lookup: Convert between file extensions and MIME types. Type one or many — works both directions. Server-side tools upload or log inputs. Just Tool It does not: it uses pure JavaScript and Web APIs (no network calls for your input). Close the tab and the working data is gone. That is zero-server processing and on-device security.
How to use MIME Type Lookup
- Open the tool on this page — no account or email required.
- Add your input by dropping a file, pasting text, or filling the form fields.
- Adjust options if available (quality, format, ranges, etc.).
- Run the tool and download (or copy) the result. Nothing was uploaded to Just Tool It.
Frequently asked questions
Is my data uploaded when I use MIME Type Lookup?
No. Just Tool It is a static web app. Your input is processed with pure JavaScript and Web APIs (no
network calls for your input). You can verify in the browser Network panel: no file payloads are sent to
our origin for processing.
Is this tool free? Do I need an account?
Yes, it is free. There is no sign-up, paywall, or trial. We do not create user accounts because we never
receive your files.
Does it work offline?
After the page and any required libraries are cached (including via the service worker / PWA), many tools
keep working without a network. Large optional engines such as FFmpeg.wasm or OCR models still need a
one-time download.
How is this different from other free online tools?
Most free tools upload files to a cloud worker. Just Tool It emphasizes zero-server processing and
on-device security: files stay in browser memory until you download the output and close the tab.