No. eCMS is a local-first tool. All data lives in your browser memory while the page is open. Nothing is sent to any server.
While you are working, the data only exists in memory. When you export, you choose where to store it: as JSON or as an encrypted .dat file on your own disk, USB drive, cloud folder or password vault.
Yes. eCMS is built so you can comfortably keep your own sensitive notes and lists in one place: passwords and access codes, personal details, private project notes, contact data, license keys and other confidential information.
The important part is how you export: use encrypted files and a strong password if the dataset contains anything you would not want others to read.
When you use Save encrypted, the dataset (schema + records) is encrypted in your browser using a password you provide. eCMS uses the Web Crypto API (AES-GCM with a key derived from your password). The result is a single opaque .dat file that you can later reopen with Open encrypted and the same password.
If you forget the password used for an encrypted file, the data cannot be recovered. There is no backdoor or password reset. Treat your key like a real safe code.
Yes. You can import and export plain JSON files using Open JSON and Save JSON. This is useful for debugging, versioning or connecting to other tools, but JSON is not protected. Do not store secrets in unencrypted JSON unless you fully trust the storage location.
eCMS is ideal for small, focused datasets: personal lists, mini-CRMs, simple inventories, password and key overviews, private journals, notes with tags, lightweight project overviews and similar use cases.
Yes. If you add a field of type file, eCMS will embed file content into the dataset when you save. This makes the resulting file larger, but completely self-contained.
Yes. Use the Download link once to generate and save a single HTML file that contains the complete eCMS app (for example eCMS.html). After that you can open that file directly in a modern browser and work fully offline.
All functionality - designing schemas, editing records and importing or exporting JSON and encrypted .dat files - keeps working offline, because everything runs entirely in your browser.
Recent versions of Chromium-based browsers (Chrome, Edge, Brave, Opera) and other modern browsers with Web Crypto support are recommended. Always keep your browser up to date.
eCMS encrypts your data locally in the browser using AES-GCM with a key derived from your password. Without that key, the encrypted file is effectively unreadable. There is no backdoor, no recovery option and no copy of your password stored anywhere.
In practice this means: if you choose a strong, unique passphrase and keep your device and browser clean, encrypted datasets are an extremely robust way to store sensitive information - from personal notes and IDs to access codes and internal documents.
The main risks are human and environmental: weak passwords, malware on the device or storing the file in places you do not fully trust. For high-risk or regulated environments, combine eCMS with normal security hygiene (up-to-date devices, backups, sensible password policies).
Yes. It is just a single HTML app. You can send the HTML file itself (for example the one generated via Download), or share the encrypted .dat datasets plus the password via a separate channel.
eCMS is free to use. If it saves you time or becomes part of your daily toolkit, you can support development:
.dat file.