> ## Documentation Index
> Fetch the complete documentation index at: https://docs.zerokeyusb.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Edit a Credential
> How to open the editor, move the cursor, use the three keyboard pages, generate random passwords and save.
This guide details every operation in the on-device editor. If you just want to create your first credential, start with the [Create your first credential](/getting-started/first-credential) guide.
***
## Step 1 — Select the credential
From the main screen, navigate to the credential you want to edit using **Left/Right**. If you have many, hold **Left/Right** to jump 10 slots at a time.
*When the right credential is on screen (you'll see its number at the top left — here `4`), move on to the next step.*
***
## Step 2 — Select the field and open the editor
The active field shows as an inverted white block on the left (globe = site, silhouette = user, padlock = password, key = 2FA). Switch between fields with **Down/Up**:
* **Site** ↓ **User** ↓ **Pass** ↓ **2FA** (if the credential has TOTP)
When you're on the right field, **hold Center for \~1 second** to enter the editor.
*A **short** Center press types the field to the host (not what you want). A **long** press (\~800 ms, until you see the large halo) opens the editor.*
***
## Step 3 — Editor anatomy
The editor looks like this:
| Element | Function |
| --------------- | --------------------------------------------------------------------------------------------------------------------------------- |
| Row 1 | Shows the current field content (**up to 32 chars**, scrolls horizontally past 16) with an inverted cursor at the insertion point |
| Row 2 — `<` `>` | Move the **field** cursor (insertion position) |
| Row 2 — KB1 | Uppercase keyboard: `A B C D E F G H I J K L M N O P` |
| Row 3 — `Rand` | Fills the field with strong random characters from the hardware TRNG (format set in Settings) |
| Row 3 — KB2 | Lowercase keyboard: `a b c d e f g h i j k l m n o p` |
| Row 4 — `Save` | Saves changes and returns to the main view |
| Row 4 — KB3 | Numbers/symbols: `0 1 2 3 4 5 6 7 8 9 - + ! @ #` |
***
## Step 4 — Move the cursor across the keyboard
When you enter the editor, focus starts on KB1 (row 2). **Left/Right** move the keyboard cursor within the current row.
*Press **Right** to advance the keyboard cursor, **Left** to go back. At the end/start, the cursor jumps to the control in the adjacent row (`Rand`, `Save`, `<`, `>`).*
***
## Step 5 — Insert a character
With the desired character under the keyboard cursor, press **Center**. It gets inserted at the field cursor's current position, which then advances automatically.
*The `L` is inserted at position 5 of the field and the field cursor advances to position 6. If you wanted to replace instead of insert, read the next step.*
***
## Step 6 — Move the **field** cursor (not the keyboard)
Sometimes you want to edit characters in the middle of the field, not just append to the end. For that, use the `<` and `>` symbols on row 2.
*Reach the `<` or `>` symbol with **Left** (from KB1) and press **Center**. The **field** cursor moves one position left or right. When it's on the position you want to edit, go back to KB1/KB2/KB3 and press **Center** on the new letter — it overwrites the existing one.*
Keyboard insertions **overwrite** the character at the current position, they don't push existing content. So "deleting" a character is simply moving onto it and entering a space (KB3, first character).
***
## Step 7 — Generate a random password
For password fields, instead of typing letter by letter, use **Rand**. It generates a strong random password (**up to 32 characters**).
The **format** follows what you picked in **Settings → `Pwd:`** (see [Menu](/firmware/menu)). Six formats are available:
| Setting label | Format | Example |
| ------------------- | ----------------------------------------------------------------- | ---------------------------------- |
| `Symbols` (default) | 32 chars from the full printable set (letters, digits, symbols) | `t7#Kp!2r$Qm9^Za5Wd8&Bv3Ln6@Xj1Qz` |
| `Numeric` | 32 digits | `48201937560428173905641820937584` |
| `a-z 0-9` | 32 lowercase letters + digits | `k3m9xq1z7r4p2n8wj5c6vb0hd1ft9gs2` |
| `Aa-z 0-9` | 32 mixed-case letters + digits | `Kp3Mx9Qz1Rt4Nb8yWd2Fc7Hj5Lv0Gs6R` |
| `Words` | Capitalised BIP39 words joined by a random separator (`-_.!@#*+`) | `Ocean-Cargo-Mint-River-Sun` |
| `Words+Num` | Same, plus a 2-digit group after the first word | `River_28_Mango_Ocean_Tiger` |
The word formats use a built-in word list and fit as many words as they can under 32 characters. `Rand` on the **site** or **user** fields always uses the full `Symbols` set regardless of this setting.
*Navigate to `Rand` with **Down** from row 2. Press **Center**: the field fills up. If you don't like it, press **Center** again to regenerate.*
***
## Step 8 — Save
When you're done, navigate to `Save` (bottom-left corner) and press **Center**. The changes are encrypted with AES-128 CBC and written to EEPROM.
*The editor closes and you return to the main view. The credential now has the changes.*
Leaving the editor without pressing **Save** **discards** the changes. There is no confirmation: the moment you change screen via any path other than `Save`, what you typed is lost.
***
## Shortcut table
| Action | How |
| ------------------------ | ------------------------------------------------------------ |
| Enter the editor | Long-press **Center** on a field |
| Move keyboard cursor | **Left/Right** |
| Change row/keyboard | **Up/Down** |
| Insert character | **Center** on the letter |
| Move **field** cursor | **Center** on `<` or `>` (row 2) |
| "Delete" a character | Move the cursor there and insert space (KB3 first character) |
| Generate random password | **Center** on `Rand` |
| Save and exit | **Center** on `Save` |
| Discard changes | Unplug USB before pressing Save |
***
## Next steps
The TOTP field is imported over USB-CDC only, not editable on-device.
Save your current state before editing many credentials.