Braille Extender

NVDA add-on that extends braille output, input, scrolling, and display-specific gestures.

• Authors: André-Abush Clause and contributors
• License: GNU General Public License v2
• Stable build: Download (stable channel)
• Development build: Download (dev channel)
• Source: GitHub — BrailleExtender

Minimum NVDA: 2024.1

After you install the add-on, you can read this same guide from NVDA: use User guide under Braille Extender in the NVDA menu, or open Help from Add-ons Manager when Braille Extender is selected.

Table of contents

1. Documentation in NVDA
2. Quick start
3. How Braille Extender relates to NVDA
4. Settings categories (overview)
5. Detailed topics
6. Feature highlights
7. Gestures and profiles
8. Feedback and contributing
9. Acknowledgements

Documentation in NVDA

Quick start

1. Install the add-on (.nvda-addon file, or the NVDA Add-on Store when it is listed there).
2. User guide: NVDA menu → Braille Extender → User guide opens this document in a browser. Use it while you explore settings and gestures. The Documentation in NVDA table above lists other menu entries.
3. Settings: NVDA menu → Braille Extender → Settings… — review the tabs you care about (for example General, Braille tables, Document formatting).
4. Gestures: NVDA → Preferences → Input gestures → Category: Braille Extender — assign the commands you will use. NVDA menu → Braille Extender → Gestures for this display… shows what your current braille display profile already defines.

How Braille Extender relates to NVDA

Braille Extender used to cover a lot of ground that NVDA did not do yet in braille. The first public release was August 2017, the same week as NVDA 2017.3, which is the version that best matches that moment in time.

NVDA’s own Settings → Braille (and related panels) have since gained options many people once relied on the add-on for. Braille Extender still adds extra behavior; check NVDA’s release notes if you want the exact wording for each item below.

Settings categories (overview)

These match the tabs in Braille Extender settings:

Detailed topics

General

• Updates: stable or development channel; automatic or manual checks (see also the add-on’s update settings).
• Say current line while scrolling: speaks the line when you pan the braille display—focus, review, both, or off. On NVDA 2025.1+, NVDA can also speak the line when using braille navigation keys; if you hear double announcements, turn off NVDA Braille → Speak when navigating by line or paragraph or reduce overlap here.
• Interrupt speech while scrolling: the add-on’s Speech interrupt when scrolling on same line checkbox is disabled on NVDA 2022.3 and later; use NVDA Braille → Interrupt speech while scrolling instead. On older NVDA you can still change the add-on checkbox.
• Skip blank lines: when panning by line, empty lines can be skipped.
• Smart Caps Lock: when this option is on and Windows Caps Lock is on, letters produced from the braille keyboard in an ordinary text field are sent with swapped case (each A–Z becomes the opposite case; other characters are unchanged). This only applies to normal typing, not when you are holding modifier keys for shortcuts. Turn it off if you want the braille table’s output exactly as translated, regardless of Caps Lock.
• Modifier / volume feedback: optional braille, speech, both, or none when modifier locks or volume change gestures are used; optional beeps with modifiers.
• Two favorite displays: pick two saved display names and use the reload gestures to switch the active braille display quickly.
• Right margin: per active braille display, in cells (up to 80 in your profile; the settings spin control may allow a higher value).
• Reverse scroll buttons: swaps which physical key means “scroll back” vs “scroll forward”.
• Terminals (braille follows review): when on, in a terminal (Command Prompt, PowerShell, PuTTY, Windows Terminal, and similar) braille follows the review cursor and stays aligned with the text you are editing, even when NVDA would usually tie braille to the focused control. When you leave the terminal, normal NVDA behavior returns. Turn off if you prefer NVDA’s default. Not available on the secure sign-in screen, or when braille is set to follow speech output only.
• Routing in edit fields: normal passes the key to NVDA; emulate arrows sends Home/End or repeated Left/Right so the caret jumps to the braille cell under the router (optional beeps). This applies when you are on the usual braille view, the system caret has focus, and you are in a terminal or editable text field.
• Announce character when routing braille cursor: when enabled, after routing the add-on speaks the character under the routing cursor using NVDA’s speech-symbol rules. On NVDA 2024.4+ this checkbox is disabled in favor of NVDA Braille → Speak character when routing cursor in text (same idea).
• Speech interrupt for unknown gestures: for braille display keys with no assigned command, controls whether NVDA stops speech when you press them. Checked (default): unassigned keys interrupt speech like most NVDA keys. Unchecked: unassigned keys do not cancel speech. Does not apply to braille typing (dots/enter), volume keys, modifier emulation, or line scroll when the scroll-interrupt rule above allows speech to continue.
• Braille keyboard configuration: shown only when your display profile defines keyboard layouts (not all displays).
• Unicode tools (assign in Input gestures): work on selected text on a web page when you have a selection; otherwise on the text at the review cursor. Convert plain text ↔ Unicode braille and Unicode braille ↔ dot numbers.
• Character information (assign in Input gestures): at the review cursor, reports Unicode name, speech symbol, braille cells, and numeric bases; double-press for a browseable block.

Braille tables

• Rotation lists: your input and output table lists are names in order, separated by commas. The next/previous table commands move through that order (assign them in Input gestures if your display profile does not already). Custom Braille Extender tables are not listed here—choose them only in the custom braille tables dialog (see below).
• Automatic table row: On NVDA 2025.1+, you can include automatic entries; the add-on resolves them with NVDA’s language-based default tables. On older NVDA, auto is not supported the same way—use explicit table files.
• Shortcut input table: optional separate table used for certain shortcuts.
• Additional Liblouis output pass: optional second output table applied after the main one (tables from your preferred output list; not inactive custom tables).
• Tabs as spaces: show tab characters as a run of spaces; tab width is per active display (range 1–42).
• Manage custom braille tables…: opens the custom-tables dialog (see below).

Table dictionaries (not in settings tabs)

Three layers work together: Global (applies to all tables), Table (for the current output table), and Temporary (short-lived overrides until you restart NVDA). If a dictionary file has errors, that layer is skipped until you fix it.

Open NVDA menu → Braille Extender → Table dictionaries → Global dictionary, Table dictionary, or Temporary dictionary.

Custom braille tables (NVDA 2024.3+)

Braille Extender can store and use your own braille tables when you select them in the manager. They apply to braille input and output through the add-on (not through NVDA → Settings → Braille or the add-on’s table rotation lists).

Requirements

• NVDA 2024.3 or later.
• Table files must be .utb, .ctb, or .tbl (not helper files such as .cti or .dis).

Where to open the manager

What you can do

To clone a custom table you already manage, use Add… → Copy from an existing table and pick it from the list (same display name as in the custom-tables list).

Add dialog

• Choose Copy from an existing table (built-in, other add-ons, or your own custom tables) or Create an empty table.
• Copy keeps the source file extension (.utb, .ctb, or .tbl).
• Create empty writes a minimal starter file as .utb, or .ctb if you mark the table contracted in the properties step.

Choosing which custom table to use

At the top of the custom braille tables dialog:

Only the table(s) you select here are active. They do not appear in NVDA → Settings → Braille or in Braille Extender’s table rotation lists, so NVDA can still start normally if the add-on is not loaded.

Press OK to apply your choice. To stop using custom tables, set both lists to None (files are kept). To delete tables permanently, use Remove in the manager.

Storage

Table files and a small settings file are saved in your NVDA user configuration folder ( NVDA menu → Preferences → General → Open NVDA user configuration directory ), under *brailleExtender\customBrailleTables*.

After you add, remove, or change tables, braille updates immediately.

Using custom tables day to day

1. Add the table (Add… → Copy from an existing table, or create an empty table).
2. In Properties, allow it for input and/or output (capabilities of the table file).
3. Set Active custom input table and/or Active custom output table to that table (or leave None for that direction).
4. Press OK. New tables are selected automatically for the directions you enabled when you add them.

If you turn the add-on off

Your custom table choice is kept in Braille Extender’s own settings so NVDA’s braille settings stay on a safe built-in table. When you enable the add-on again, your custom selection comes back.

Tables from other add-ons (NVDA 2024.3+)

You do not need to copy a table into Braille Extender’s folder. Tables from another add-on (for example Experimental braille tables) or NVDA’s scratchpad work like built-in tables: add them to your rotation lists, switch to them with the table commands, or use them as the additional output pass. On NVDA 2024.1–2024.2, only NVDA’s built-in tables are supported.

If a table file is missing

The add-on falls back to a safe table where it can and clears broken entries from your lists so braille keeps working.

Document formatting

Braille Extender does not replace NVDA’s Document formatting dialog. The Document formatting settings tab adds a separate braille layer:

• Per category: each row is Follow NVDA document formatting, enabled, or disabled (see the panel description at the top of the tab).
• Plain text mode — disable all text formatting from this layer.
• Process formatting line per line — build braille one line at a time.
• Report rows — one combo per category (font attributes, emphasis, alignment, colors, links, headings, lists, tables, cell coordinates, spelling/grammar, and others listed on the tab).
• Level of items in a nested list — show list nesting level in braille.
• Methods… — per-attribute display (nothing, hand over to the table, dots 7/8, tags, line padding for alignments, etc.).
• Tags… — start/end tag strings used by tag-style methods.

On NVDA 2024.4+, NVDA also has global braille formatting options; this tab remains the add-on’s row-by-row control.

Object presentation

This tab changes what appears on the braille display when NVDA shows one object at a time—the summary line for the focused control (button, link, table cell, and similar). It does not change how NVDA speaks object information; use NVDA Settings → Object presentation for speech options.

Order properties…

Open Object presentation → Order Properties… to set which parts come first, reading left to right on the display. Parts with no content for the current object are skipped.

You can reorder these fields (labels match the dialog):

• name, value, state, role text (type of control, for example heading level)
• description, keyboard shortcut, position info (shown as 3/10 in braille, not “3 of 10”)
• position info level (outline level, lv 2)
• current labels (for example “current page” on the web)
• place-holder, cell coordinates text

Reset to the default NVDA order — same order as NVDA without this add-on (name, then value, state, role text, and so on).

Reset to the default add-on order — puts state and cell coordinates before name (default for new profiles).

What still follows NVDA

• Description, keyboard shortcut, and position only appear if the matching options are enabled in NVDA Settings → Object presentation.
• Cell coordinates also follow Braille Extender → Document formatting → Cell coordinates.

Row and column headers from the application may still be added after the main summary when available.

Selected elements

Selected elements controls how a selected item is marked on that object summary line:

When the choice is not nothing and the object has a name, the words selected and selectable are omitted from the state text so you are not told “selected” twice. Highlighting inside running text still follows NVDA’s own show selection setting.

Progress bar output using braille messages

When a progress bar’s value changes, the add-on can show a short message on the braille display (speech is unchanged—use NVDA Settings → Object presentation → Progress bar updates for speech):

Report background progress bars

The three choices (Follow NVDA document formatting, enabled, disabled) use the same wording as on the Document formatting tab, but here they only decide which windows’ progress bars can trigger the braille messages above:

Excel

Open Braille Extender settings → Excel to control how Microsoft Excel worksheet cells appear in braille. These options are for the desktop Excel program when NVDA can read cells on the sheet the same way it does when you move around with the arrow keys. They do not apply to other spreadsheet programs (for example LibreOffice Calc or sheets in a web browser).

If you previously used Document formatting → Cell formula, that option has moved here. When you update the add-on, your previous on/off choice is copied into Excel → Report cell formulas in braille automatically.

Report cell formulas in braille

When this box is checked (default), the add-on can show formulas on the braille display, not only the value you see in the cell. When it is unchecked, Excel cells behave like standard NVDA braille with no formula line from this add-on.

Without the add-on, NVDA often shows a short frml hint when a cell has a formula. With Focused cell only (below), you still get the normal cell line (value, coordinates, and so on), and the full formula is added after that—so you read the formula itself instead of only frml.

Braille view

This setting controls how much of the sheet appears on the braille display at once:

Row and column range views are meant for skimming nearby cells without moving focus cell by cell.

You can also change Braille view from the keyboard while Excel is running: in NVDA → Preferences → Input gestures, assign Cycle Excel braille view (focused cell, row range, or column range on one line) (listed under Braille Extender). There is no default shortcut; each press moves through Focused cell only, Row range on one line, then Column range on one line, and back to the start. The gesture only works when Report cell formulas in braille is enabled.

In Focused cell only view, braille panning behaves like normal NVDA (your place on the line is kept when you move between cells). In Row range on one line or Column range on one line view, the focused cell is kept at the left of the braille display when you move to another cell, so the overview line stays aligned.

Formulas on row or column line

This list applies only when Braille view is Row range on one line or Column range on one line:

Cells on each side of focus

When Braille view is Row range on one line or Column range on one line, this number is the maximum cells to the left and right of your cell (on a row) or above and below (in a column) that can appear on the line. Default is 9 (up to 19 positions: 9 + your cell + 9). You can set 0 to 50.

The line is usually shorter than that maximum: it runs from the first to the last non-empty cell in the window. Empty cells between two cells that have content still appear as blank gaps on the line.

Separator between cells on the line

Text placed between each cell on a row or column line. Default is a space, vertical bar, space: |. You can change it (for example to - or ,) to suit your reading style.

Row and column line prefixes

When Braille view is Row range on one line or Column range on one line, a short prefix is shown at the start of the braille line, before the current cell address. NVDA adds one space after the prefix automatically—do not put a trailing space in the setting.

Leave a field empty to use the translated default for your NVDA language. Type your own short label (for example R or Ln) if you prefer something different on the display.

How a row or column line looks

Examples (default separator and prefixes):

• Row 2, you are in A2 with value Hello, empty B2–F2, value 99 in G2:
  row A2: Hello | | | | | | 99
• The prefix (row or col by default, or your custom text) shows whether the line is a row range or a column range; the current cell address (A2:) comes immediately after that prefix and a single space.
• Only the current cell uses its address in the line (for example A2: Hello). Other cells show only their value (or nothing if empty).
• Empty cells between two cells with content appear as separator with nothing between (for example | |).
• Row and column headers you have set up in the workbook (the extra labels NVDA can announce for the current cell) are shown after the current cell’s part of the line, not after every neighbor.

Routing keys on a row or column line

When Braille view is Row range on one line or Column range on one line, each part of the line is tied to one cell:

• Press a routing key on the current cell’s value (for example under Hello in A2: Hello) to edit that cell, like routing on a normal Excel cell in NVDA.
• Press a routing key on a neighbor’s value (or on an empty gap for an empty cell) to move to that cell.

So you can jump along the row or column from the braille display without arrowing through every cell.

Merged cells

If several columns or rows are merged into one cell:

• The value is shown once at the start of the merged area on the line (not repeated in every column or row of the merge).
• Other positions covered by the merge appear as empty slots on the line, but routing there still takes you to that merged cell.
• The current cell shows the full merged address when NVDA reports it that way (for example B2 through D2), and you still see its value or formula when you are anywhere in that merge.

Undefined character representation

Characters not defined in the active output table (including many emoji) use the chosen method: use braille table behavior, full 1–8 or 1–6 dot cell, empty, custom dot pattern (for example 6-123456), question mark, custom sign (for example ??), hex (table style, HUC8, HUC6), decimal, octal, binary.

Descriptions: optional character description, extended description, full extended, optional size line, optional Unicode data as a last resort, and an exclude list (character codes or ranges) so description is skipped for ranges you find noisy.

Precedence: table rules and table dictionaries take priority over descriptions; descriptions take priority over the generic undefined pattern.

More on HUC: danielmayr.at/huc

Advanced input mode

Settings tab: escape sign for numeric/Unicode input and exit after one character.

Menu dialog: NVDA menu → Braille Extender → Advanced input mode dictionary… — abbreviation entries per input table (separate from table dictionaries).

Toggle advanced input (defaults include NVDA+Windows+i or ⡊+space). While active:

• HUC8: type the Unicode HUC8 braille pattern for the character; the add-on waits until the sequence is valid and complete, then inserts the character (many symbols need about four cells; some need more—see the HUC site). Works for emoji and other supported code points.
• Numeric bases: after the escape sign, send ⠭ or ⠓ (hex), ⠙ (decimal), ⠕ (octal), ⠃ (binary), type digits, then Space.
• Abbreviations: stored in the advanced input mode dictionary (menu dialog above; one entry per abbreviation and table). If you add the same abbreviation twice, the new text replaces the old one. Expand with abbreviation + Space.

HUC6 input is not implemented.

One-handed mode

Compose a cell in several steps—useful if you type with one hand. In Braille Extender settings, the three methods appear in this order: Fill a cell in two stages using one side only, Fill a cell in two stages using both sides, Fill a cell dots by dots. Toggle one-handed mode with NVDA+Windows+h (often ⡂+space on supported displays). If the stored method is unknown, the add-on speaks unsupported and clears any partly typed cell.

One side only (two steps on one bank; Space = empty half)

First step: dots 1–2–3–7. Second step: 4–5–6–8. Space means “this half is empty”. Space twice gives a completely empty cell.

• ⠛: 1–2 then 1–2, or 4–5 then 4–5
• ⠃: 1–2 then Space, or 4–5 then Space
• ⠘: Space then 1–2, or Space then 4–5

Both sides (left bank, then right bank)

Type left bank dots, then right bank. If one side is empty, press the same dots twice, or enter the non-empty side in two steps.

• ⠛: dots 1–2, then 4–5
• ⠃: 1–2 then 1–2, or 1 then 2
• ⠘: 4–5 then 4–5, or 4 then 5

Dot by dot (toggle)

Each key press flips a dot. Press Space when the cell is the one you want.

⠛ can be built as: 1–2 then 4–5 then Space; or 1–2–3, dot 3 again to correct, then 4–5, Space; or 1, then 2–4–5, Space; and other paths.

Speech History Mode

Do not confuse this with NVDA’s shortcut for toggling braille mode (NVDA+Alt+t).

In current NVDA (see Commands Quick Reference → Braille and Input help):

• NVDA+Alt+t — Toggle braille mode (shortcut documented since NVDA 2024.2, which added display speech output mode: braille can mirror what NVDA speaks). NVDA cycles its braille modes, including display vs speech output. That is still not Braille Extender’s separate speech history list and routing workflow.

What Braille Extender does instead

While Speech History Mode is on, the add-on records what NVDA speaks as plain-text lines you can browse, uses line scroll on the display to move through that list, and switches the braille line to show those lines instead of the usual focus or review text. Turning the mode off returns braille to normal and refreshes the display.

• Assign a gesture: the add-on does not ship a mandatory desktop shortcut—use Input gestures → Braille Extender → Turn Braille Extender speech history mode on or off… Many display profiles use a gesture such as ⡞+space; use Gestures for this display… to see yours.
• Gesture conflict: avoid mapping this add-on command to NVDA+Alt+t unless you mean to replace NVDA’s toggle braille mode command on that key.
• While browsing history: speech is captured as text only (no sounds or tones in the list); the forward/back line commands move through stored lines when you are in this mode.
• Limit: how many lines to keep (the settings panel allows a very high maximum).
• Number entries: each line is prefixed with # and the entry number (padded with leading zeros so all numbers use the same width), then : and the text—for example #3: or #0003: depending on your history limit.
• Speak entries: optionally read the line aloud when you move in the history.
• Routing: the leftmost routing key copies the current line; the rightmost opens browseable text; middle keys jump forward or backward in the list depending on which side of the display you press.

Rotor

The rotor switches active quick-nav / review category. Categories include text navigation, selection, object / review, links (visited/unvisited), landmarks, headings (per level), lists, form controls, tables, same/different formatting, input/output table lists, and more.

• Settings: enable/disable each category and set master order. Only enabled items appear when cycling.
• Which categories appear: in browse mode–style views (many web pages, similar documents, and some app views with quick navigation), the add-on asks NVDA whether each rotor type is supported; types that would always fail (for example some formatting jumps in certain Word views) are hidden so you are not stuck on “not supported”.
• Gestures: assign next/previous rotor item and next/previous rotor set in Input gestures; display profiles may already bind them.

Auto scroll

When auto scroll is on, the display advances by itself on a timer while you stay on the usual braille view. If you switch to another view (for example speech history), auto scroll pauses until you return.

• Delay: stored per braille display model, between about 0.2 and 42 seconds between steps (default about 3 seconds).
• Faster / slower keys: each press changes the delay by a configurable step (roughly 25 ms up to 7 s per step, depending on settings).
• Adjust to content: the delay can shorten or lengthen based on how much of the current line fits on your display.
• Ignore blank lines: optional skip of empty lines while auto scrolling.
• Beeps when turning auto scroll on or off.

Role labels

When Use custom role labels is checked, you can edit role, landmark, and positive / negative state labels per language from this panel (stored with your other Braille Extender settings). When unchecked, NVDA’s default labels apply.

Advanced

• Avoid cursor positions issues with some characters such as variation selectors — improves braille alignment when certain Unicode characters (variation selectors) are next to letters.
• Force the refresh of braille region related to foreground object — updates the display when the focused item’s name changes often (timers, live counters, changing window titles).

Feature highlights

• Reload two favorite braille displays with shortcuts.
• Terminals: braille can follow the review cursor while you edit (PuTTY, PowerShell, cmd, bash, …).
• Auto scroll with timing and blank-line options.
• Multiple input/output tables and automatic selection on NVDA 2025.1+.
• Custom braille tables (add, copy, edit) on NVDA 2024.3+; activate only from the custom-tables dialog (None = off).
• Dots 7/8, tags, and line padding for structure and attributes (document formatting Methods).
• Hide/show dots 7 and 8 — command in Input gestures (not an Advanced settings checkbox).
• Second translation pass (optional extra output table after the main one).
• Tabs as spaces; reverse scroll buttons.
• Speak current line while scrolling (coordinate with NVDA’s braille speech options).
• Unicode braille and cell-description tools for the selection.
• Lock braille keyboard; lock modifiers from braille.
• Quick launches and table dictionaries (NVDA menu → Braille Extender).
• One-handed input; undefined characters (including emoji); advanced input and abbreviations.
• Speech History Mode; extended display gesture maps where profiles exist.

Gestures and profiles

• Keyboard: listed under Input gestures → Category: Braille Extender. Gestures for this display… shows bindings for your current braille display profile (including display-specific keys when a profile exists).
• Braille display: some displays ship with a predefined gesture map. If yours does not, assign commands in Input gestures like any other NVDA command.
• Not in settings tabs (menu or Input gestures only): hide/show dots 7–8, lock braille keyboard, lock modifier keys, quick launches, table dictionaries, advanced input dictionary, custom braille tables manager, table overview, Unicode tools, character information, and others—search Braille Extender in Input gestures to browse them.

Feedback and contributing

Bug reports, suggestions, and pull requests are welcome on GitHub — BrailleExtender. If you change user-visible text or behavior, please update this guide and any translations you maintain so everyone stays in sync.

If you work on the source code, build steps and developer tooling are described in the repository on GitHub (not in this user guide).

Acknowledgements

• Copyright: © 2016-2026 André-Abush Clause and other contributors — see addon page.

Translators

• Arabic: Ikrami Ahmad
• Chinese (Taiwan): 蔡宗豪 Victor Cai <surfer0627@gmail.com>
• Croatian: Zvonimir Stanečić <zvonimirek222@yandex.com>
• Danish: Daniel Gartmann <dg@danielgartmann.dk>
• English and French: Sof <hellosof@gmail.com>, Joseph Lee, André-Abush Clause <dev@andreabc.net>, Oreonan <corentin@progaccess.net>
• German: Adriani Botez, Karl Eick, Rene Linke, Jürgen Schwingshandl
• Hebrew: Shmuel Naaman, Afik Sofer, David Rechtman, Pavel Kaplan
• Italian: Simone Dal Maso, Fabrizio Marini
• Persian: Mohammadreza Rashad
• Polish: Zvonimir Stanečić, Dorota Krać
• Russian: Zvonimir Stanečić, Pavel Kaplan, Artem Plaksin
• Spanish: Eric Duarte Quintanilla
• Turkish: Umut Korkmaz
• Ukrainian: VovaMobile

Code and third-party

• Speech History Mode feature: Emil Hesmyr <emilhe@viken.no>
• Maintenance / cleanup: Joseph Lee <joseph.lee22590@gmail.com>
• Attribra (third-party): Copyright © 2017 Alberto Zanella — attribra

Thanks also to Daniel Cotto, Daniel Mayr, Dawid Pieper, Corentin, Louis, and everyone who reported feedback.