Hex Studio

A fast, cross-platform hex editor for Intel HEX, Motorola S-record, and raw binary files, built with Tauri 2, SvelteKit, and Rust.

Load an ASAM MCD-2 MC (A2L) description alongside the image and it also becomes a calibration editor: named parameters with their physical values, curves and maps you can edit in place, and ASAM CDF 2.1 (CDFX) import and export.


Hex view — with the segment list and data inspector	Map editor — shaded grid and the slice as a 3D surface

^{Screenshots show real values decoded from the ASAM ASAP2 demo image; regenerate with docs/screenshots/capture.sh.}

Features

File Handling

Open Intel HEX (.hex, .ihex), Motorola S-record (.srec, .mot, .s19, .s28, .s37), and raw binary (.bin) files via native OS file picker
Drag and drop a file directly onto the window to open it
Save As to Intel HEX or S-record with automatic format conversion; export to flat binary with configurable fill byte
Import Binary — load a raw .bin file at a user-specified base address
Format auto-detection from file extension and magic bytes
OS file-association open — double-clicking an associated file in the OS file manager launches the app and loads the file directly

Hex Viewer

Virtual scrolling — renders only visible rows, handles files of any size without performance degradation
Configurable bytes per row: 8, 16, or 32
Address column, hex byte columns (with mid-row gap at byte 8), and ASCII representation
Alternating column shading and row hover highlighting; clickable bytes pin the Data Inspector
Non-printable bytes rendered as .
Segment boundary visualisation — non-contiguous memory regions are separated by a gap row showing the gap size and address range; leading blank cells show where a segment starts mid-row

In-Place Editing

Type over any byte — double-click a byte in either the hex or the ASCII column and type two hex digits. The cell highlights while the first nibble is pending, and the caret advances to the next byte once the pair completes. Tab confirms and advances, Enter confirms and stays, Escape cancels. Only bytes that exist can be edited; gaps between segments are not writable this way
Undo / Redo (⌘Z / ⌘⇧Z) — every operation below is one entry on a 50-step history; the window title carries a ● while there are unsaved changes
Cut / Paste / Delete on a byte selection, through an internal binary clipboard kept separate from the system clipboard so it can hold raw bytes rather than text. Paste writes at the selection start, or at the top visible address when nothing is selected; the right-click menu additionally offers paste into empty space only
Select Range… (⌘⇧A) — select an exact address span by typing its start and end, for ranges too large to drag

Edit Operations

Fill Selection… — repeat a hex pattern (FF, or DE AD BE EF) across the selection, or check Randomize to fill with random bytes. Warns when the pattern does not divide evenly into the range
Move Selection… — relocate the selected bytes to a new base address
Import from File… — merge an IHex, S-record or binary file into the current one, with a preview of the segments it would add
Insert Checksum… — compute XOR, sum-8, CRC-16 or CRC-32 over a range and write the result back into the image at a chosen address, with selectable width (1/2/4 bytes) and byte order (LE/BE). Start, end and target addresses are pre-filled from the file's own layout

Fill, Move, Paste and Import each offer two write modes: overwrite existing, or fill empty only — the latter writes solely into address gaps, leaving existing data untouched.

Physical Data View (A2L)

Load an ASAM MCD-2 MC description (.a2l) and the image stops being bytes and becomes named, converted parameters.

Load via File > Load associated A2L… (⌘⇧D), the toolbar's drop target, or by dropping an .a2l file on the window
The A2L last used with a given hex file is remembered and pre-filled, but never auto-loaded — the association is a hint, and silently decoding against the wrong description is worse than asking
hex / data toggle in the toolbar switches between the byte view and the parameter view; the segment list and data inspector belong to the hex view and are hidden (not forgotten) in the data view
Coverage banner: objects in the image, partial, absent, virtual, described and undescribed bytes, and the percentage of the image the description accounts for
Absent parameters — a show / hide link beside the Absent count keeps them out of every category but Not in image, where they always appear. Loading a description defaults to hiding them only when they are more than a tenth of the objects: a few missing among the present ones is useful context, but a description matching almost nothing buries the handful that decoded
Categories sidebar filters by shape — Scalars, Axes, 1D curves, Maps & cubes, Strings, Virtual, Not in image — each with a live count. Unsupported appears only when a file actually contains one
Columns: Name, Address, Type, Raw and Physical, individually resizable; Address, Type and Raw are toggleable in Preferences (only Type is on by default)
Decimals stepper overrides the A2L FORMAT for every fractional value at once
MEASUREMENT objects can be shown alongside characteristics (Preferences) — useful when reading a RAM dump rather than a calibration image

Editing Physical Values

Every edit is encoded in Rust and applied through the same write path as a hex edit, so it joins the same undo history and modified flag.

Scalars — typed directly, with a slider spanning the declared limits and stepping by one raw LSB, so it can only land on values the field can actually store
Enumerations — chosen from the labels the COMPU_METHOD defines, for scalars, curve points and map breakpoints alike. A verbal value is written by name, since such a conversion has no numeric inverse
ASCII strings — edited as text, limited to what the array holds including its terminator
1D curves and axes — an axis→value point table, with a plot above it that follows the draft as you type rather than waiting for the commit
Jump to bytes — any parameter's address opens the hex view at that offset, and a curve referencing a shared axis links to the object that owns it

Maps, Cuboids and Cubes

MAP, CUBOID, CUBE_4 and CUBE_5 decode and encode in full.

The detail pane shows a shaded grid preview, elided to fit, with the object's shape (4 × 5) and one row per axis
Edit values… opens a full-size grid: X breakpoints across the top, Y down the side, cells editable in place, shading on a value ramp
Anything beyond two dimensions gets a slice selector per extra dimension, reducing a cuboid or cube to a plane
A family-of-curves plot draws each row of the visible slice; hovering a row in the grid traces its curve and the reverse. Every curve shares one vertical scale, pinned to the whole object, so slices stay comparable as you step through them
A 3D surface view of the same slice, in place of the curves. Drag to orbit, arrow keys to rotate, Home to reset; cells use the grid's own shading, so the two views agree about where the highs are
- Axes are placed at their true breakpoints wherever those are numeric, so an axis running 0…5 then 13, 15 shows as bunched columns and a wide gap rather than an even mesh that hides it. A verbal axis has no coordinate to place, so it falls back to even spacing and the caption says so
- Drawn as plain SVG: a map is a height field, so cells cannot intersect and painting them back to front by their footprint is exact — no depth buffer and no WebGL

Which breakpoints can be edited depends on where the bytes are:

Axis	Data lives in	Editable
`STD_AXIS`	this object's own record	yes
`COM_AXIS`, `RES_AXIS`	a shared `AXIS_PTS` object	on that object — linked from the grid
`CURVE_AXIS`	another characteristic's values	on that object
`FIX_AXIS`	the A2L itself (`FIX_AXIS_PAR` / `_DIST` / `_LIST`)	no — it occupies no image bytes

Calibration Data Exchange (CDFX)

Import and export ASAM CDF 2.1 files. Both entries stay disabled until an A2L and a hex file are loaded, since neither half means anything alone.

Import shows what would change before anything is written: how many parameters would change, already match, were skipped and why, and which names the A2L does not define — then applies the whole set as one undo entry
Differences are compared as stored bytes rather than physical values, so a value that rounds to the same raw is correctly reported as no change
Export writes every value the description can decode, with SW-ARRAYSIZE for real grids, one SW-AXIS-CONT per dimension, shared axes as references, and verbal values as their labels
Numbers are written at round-trip precision rather than display precision, so re-importing an export does not rewrite the image
Dropping a .cdfx file on the window opens the same preview

Spreadsheet Export

File > Export Values as Excel… writes every decoded value to an .xlsx, one row per value — 673 rows for the ASAM demo description. Export only; nothing reads a spreadsheet back.

The Index column says where each value sits: Scalar or String for the single-valued shapes, otherwise a 0-based tuple in A2L dimension order — (3) along a curve, (2,1) in a map, (2,1,3,1) in a CUBE_4. The first component varies fastest, matching MATRIX_DIM and the storage order.
Breakpoints carries the axis values at that position in the same shape, (3, 15), so a row can be read on its own. A verbal axis reads as its label.
A one-dimensional object also gets its breakpoint as a number, in Axis value, which is what makes a curve chartable in Excel directly.
Numbers are written as numbers, not text. That is the reason for a workbook rather than CSV: a comma-separated file opens as a single column wherever the locale expects ; as the separator and , as the decimal mark.
Objects that could not be decoded still get a row, with the value columns empty and In image saying why, so the export and the object count agree.

Columns: Name, Description, Category, Index, Breakpoints, Axis value, Value, Text, Unit, Address, Type, Conversion, Conversion type, In image. The header row is frozen and filtered.

A2L Constructs Supported

Conversions: IDENTICAL, LINEAR, RAT_FUNC, TAB_INTP, TAB_NOINTP, TAB_VERB, COMPU_VTAB_RANGE, and FORM with a built-in expression parser (FORMULA_INV for the inverse)
Record layouts: field placement by declared position with MOD_COMMON / per-layout alignment padding, RESERVED fields, NO_AXIS_PTS_*, AXIS_PTS_X/Y/Z/4/5, AXIS_RESCALE_X
Storage order: INDEX_INCR / INDEX_DECR per axis, and ROW_DIR / COLUMN_DIR for function values
BIT_MASK fields, read and written as a read-modify-write so neighbouring fields in the same word survive
VIRTUAL_CHARACTERISTIC — evaluated from its formula and its input parameters, and reported as computed rather than as missing data
MATRIX_DIM, including the pre-1.7 spelling that pads a flat array out to three dimensions
Byte order from MOD_COMMON or per object; FORMAT from the object or its COMPU_METHOD

Copy Selection to Clipboard

Right-click context menu on any selected byte range offers six copy formats:
- Hex string (spaced) — 4D 5A 90 00
- Hex string — 4D5A9000
- C array — { 0x4D, 0x5A, 0x90, 0x00 }
- Python bytes — b'\x4d\x5a\x90\x00'
- Base64 — TVqQAA==
- ASCII / UTF-8 string — printable characters; non-printable bytes rendered as ·
- UTF-16 LE / UTF-16 BE string — shown only when the selection has an even byte count
Each menu item shows a live truncated preview of the formatted value
Clipboard writes are plain-text only (no RTF/HTML side-car types) via arboard directly on the native pasteboard

Binary File Comparison (Diff Viewer)

File > Compare with… or toolbar button opens a second file picker; a dedicated comparison window appears with:
- Side-by-side hex display (16 bytes per row, no ASCII column) of the reference and compared files
- Virtual scrolling — diff views of large files render instantly
- Byte-level highlighting: identical bytes in normal colour, differing bytes highlighted in red/orange
- Gap markers between identical regions showing the address span (0x00001000 – 0x00001FFF) of skipped identical bytes
- Expand / collapse individual identical sections by clicking their gap marker; collapsed gaps remain linked to both files' addresses
- Processing spinner shown during initial computation; uses a double requestAnimationFrame pattern so the UI paints before the heavy JS work runs
Optimised IPC: a single parse_file Rust command reads and parses IHex/SREC in one call, eliminating the double round-trip; byte lookups use Uint8Array typed arrays (~5× faster than Map)

HTML Export — Diff Report

Export as HTML… link in the diff legend bar opens an options dialog:
- Show paths: toggle display of full file paths vs. filenames only
- Sections: export all collapsed, all expanded, or as currently shown on screen
Generates a fully self-contained HTML file with embedded CSS, dark/light themes (prefers-color-scheme), and no external dependencies
Difference statistics section: compared bytes, identical bytes, different bytes
File paths aligned in columns (reference right-aligned, compared left-aligned)
Footer watermark: Difference report generated by Hex Studio
Default filename: diff-<ref>-<cmp>.html

HTML Export — Hex Report

File > Export as HTML… or the toolbar download icon opens an options dialog:
- Show ASCII column (default on)
- Show full file path in the report header (default off)
- Columns: 8, 16, or 32 bytes per row — independent of the current viewer setting
Generates a self-contained HTML file with the same visual style as the viewer (dark/light themes)
Statistics section: total bytes, address range (0x… prefix), segment count
Footer watermark: Hex export generated by Hex Studio
Default filename: <stem-of-file>.html

Search & Navigation

Find panel (⌘F / Ctrl+F) — floating, draggable, non-blocking
- Text search with case-sensitive option
- Hex pattern search (e.g. DE AD BE EF)
- Forward / Backward direction with Wrap Around
- Find / Find Next for sequential navigation
- Find All — lists every match address; click any entry to navigate
Go to Address (⌘G / Ctrl+G) — jump to any hex address in the loaded file

Side Panels (View menu or ⌘⇧L / ⌘⇧I)

Segment List — lists all non-contiguous memory segments with start address, end address, and size; click a row to scroll the viewer to that segment
Data Inspector — displays the bytes at the current address decoded as u8, i8, u16/u32/u64 (LE & BE), f32/f64 (LE & BE); address follows the scroll position or is pinned by clicking a byte
Both panels are independently togglable; their visibility is persisted across sessions

Preferences (⌘,)

Theme: System / Dark / Light (CSS custom-property based, applied globally)
Font size: 10 – 20 px slider
Bytes per row: 8, 16, or 32
Data view columns: show or hide Address, Type and Raw — the detail pane always shows all of it, so nothing is ever made unreachable
Show measurements: include MEASUREMENT objects in the data view alongside characteristics

OS File Associations

Build-time associations for Intel HEX and S-record extensions (registered via OS installer / Info.plist)
Runtime dialog (View → File Associations…) — shows the current association status for each extension including .bin, with checkboxes and an Apply button
- Windows: HKCU\Software\Classes registry + SHChangeNotify
- macOS: Launch Services LSSetDefaultRoleHandlerForContentType (association only; deassociation not supported by the OS API)
- Linux: xdg-mime default

User Interface

Native macOS menu bar — File (Open, Save as, Export as HTML, Import Binary, Load A2L, Import/Export Calibration Data, Compare with…), Edit (Undo, Redo, Cut, Paste, Delete, Select Range, Fill, Move, Import from File, Insert Checksum), Search, View, Preferences
- The system-injected Writing Tools and AutoFill items are removed from the Edit menu, which are meaningless for a hex editor
Toolbar with icon buttons: Open · Save · Export HTML · [divider] · Find · Go to Address · [divider] · Compare · [divider] · Undo · Redo · Select Range · Fill · Move · Checksum · Import Merge · [auto-spacer] · Settings
- Edit icons are context-aware: those needing a selection stay disabled until one exists, and Undo/Redo follow the history
Status bar — loading progress, navigation results; errors shown as native OS dialogs
Window size and position persisted across sessions via tauri-plugin-window-state; default launch size 925 × 460
OS window title updated with the currently open filename

Cross-Platform

macOS .app + .dmg, both Apple Silicon and Intel — released builds are signed and notarised
Windows .msi + .exe (via GitHub Actions Windows runner)
Linux .deb / .AppImage (via GitHub Actions Ubuntu runner)
Full icon set: .icns (macOS), .ico (Windows, 7 sizes), .png (Linux)

Development Toolchain

Component	Technology	Version
App framework	Tauri 2	2.x
Frontend	SvelteKit + Svelte 5	5.x
Build tool	Vite	6.x
Backend / commands	Rust	stable (1.94+)
IHex parsing	`ihex` crate	3.0
A2L parsing	`a2lfile` crate	3.5
CDFX (XML)	`quick-xml` crate	0.41
Excel export	`rust_xlsxwriter` crate	0.96
File I/O	`memmap2` crate	0.9
Serialisation	`serde` + `serde_json`	1.0
Native clipboard	`arboard` crate	3.x
Native dialogs	`@tauri-apps/plugin-dialog`	2.x
Window state	`tauri-plugin-window-state`	2.x
Package manager	npm	11.x

Getting Started

Prerequisites

Tool	macOS	Windows	Linux
Rust toolchain	`curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs \| sh`	rustup.rs	same
Node.js LTS	nvm or nodejs.org	nvm-windows	nvm
Xcode CLT	`xcode-select --install`	—	—
WebView2	—	pre-installed on Win 10/11	—
`webkit2gtk`	—	—	`sudo apt install libwebkit2gtk-4.1-dev`

Run in development mode

git clone https://github.com/brice-fr/hex-studio.git
cd hex-studio
npm install
npm run tauri dev

Hot-reload is active for both the Svelte frontend and Rust backend.

Build a release

macOS DMG:

npm run tauri build
# → src-tauri/target/release/bundle/dmg/Hex Studio_0.3.4_aarch64.dmg

# For an Intel Mac, or to check the cross-build before tagging:
rustup target add x86_64-apple-darwin
npm run tauri build -- --target x86_64-apple-darwin
# → src-tauri/target/x86_64-apple-darwin/release/bundle/dmg/Hex Studio_0.3.4_x64.dmg

Windows MSI (requires Windows or GitHub Actions):

npm run tauri build
# → src-tauri/target/release/bundle/msi/Hex Studio_0.3.4_x64_en-US.msi

Automated releases via GitHub Actions

Push a version tag to trigger a multi-platform build:

git tag v0.3.4
git push origin v0.3.4

The workflow (.github/workflows/release.yml) builds the macOS bundles — both architectures off one Apple Silicon runner, since x86_64 cross-compiles — and the Windows bundles, then attaches them to a draft GitHub Release.

Project Structure

hex-studio/
├── src/                          # SvelteKit frontend
│   ├── lib/
│   │   ├── api.js                # Tauri invoke abstraction layer
│   │   ├── editOps.js            # Record-level edit primitives + checksums
│   │   ├── mapGrid.js            # Grid index arithmetic, slicing, shading
│   │   ├── plot.js               # Screen geometry for the parameter plots
│   │   ├── surface.js            # 3D projection and depth ordering for maps
│   │   ├── hexHtmlExport.js      # Hex viewer HTML report generator
│   │   └── components/
│   │       ├── HexViewer.svelte        # Virtual-scrolling hex display + copy menu
│   │       ├── FileMenu.svelte         # Toolbar icon buttons
│   │       ├── HexExportDialog.svelte  # Hex HTML export options dialog
│   │       ├── DiffViewer.svelte       # Side-by-side binary diff + HTML export
│   │       ├── CompareDialog.svelte    # File picker for diff comparison
│   │       ├── FindDialog.svelte       # Floating search panel
│   │       ├── GoToDialog.svelte       # Go-to-address modal
│   │       ├── SaveFormatDialog.svelte # Format picker modal
│   │       ├── AboutDialog.svelte      # About modal
│   │       ├── SegmentList.svelte      # Segment list side panel
│   │       ├── DataInspector.svelte    # Data inspector side panel
│   │       ├── PreferencesDialog.svelte# Preferences modal
│   │       ├── FileAssocDialog.svelte  # File associations modal
│   │       ├── SelectRangeDialog.svelte# Select an address range by typing it
│   │       ├── FillDialog.svelte       # Fill selection with pattern or random
│   │       ├── MoveDialog.svelte       # Relocate selection to a new address
│   │       ├── ChecksumDialog.svelte   # Checksum algorithm, width, endianness
│   │       ├── ImportMergeDialog.svelte# Merge another file into this one
│   │       ├── DataView.svelte         # A2L parameter table + coverage stats
│   │       ├── ParamDetail.svelte      # Parameter editor, point table, plot
│   │       ├── MapGrid.svelte          # One 2D slice, preview or editable
│   │       ├── MapEditor.svelte        # Full-size map grid overlay
│   │       ├── MapPlot.svelte          # A map as a family of curves
│   │       ├── MapSurface.svelte       # A map as an orbitable 3D surface
│   │       └── CdfxImportDialog.svelte # CDFX import preview and statistics
│   └── routes/
│       ├── +page.svelte          # App shell and native menu
│       └── compare/
│           └── +page.svelte      # Diff viewer window
├── src-tauri/
│   ├── src/
│   │   ├── main.rs               # Entry point
│   │   ├── lib.rs                # Tauri builder + plugin registration
│   │   ├── commands.rs           # Tauri command handlers
│   │   ├── file_operations.rs    # File I/O, IHex & SREC writers
│   │   ├── hex_parser.rs         # Intel HEX parser
│   │   ├── srec_parser.rs        # Motorola S-record parser
│   │   ├── a2l.rs                # Tauri bridge to the a2l-data crate
│   │   └── file_assoc.rs         # OS file association management
│   ├── crates/a2l-data/          # A2L decoding and encoding (own crate)
│   │   ├── src/db.rs             # Parsed A2L, object resolution, index maths
│   │   ├── src/layout.rs         # RECORD_LAYOUT to byte offsets
│   │   ├── src/convert.rs        # COMPU_METHOD, both directions
│   │   ├── src/formula.rs        # FORM / VIRTUAL expression parser
│   │   ├── src/decode.rs         # Bytes to physical values
│   │   ├── src/encode.rs         # Physical values back to bytes
│   │   ├── src/cdfx.rs           # ASAM CDF 2.1 read and write
│   │   ├── src/sync.rs           # CDFX import planning and export
│   │   ├── src/export.rs         # One row per value, for the spreadsheet
│   │   └── tests/demo_file.rs    # End-to-end against the ASAM demo pair
│   ├── icons/                    # Full icon set (icns, ico, png)
│   ├── capabilities/             # Tauri ACL permissions
│   └── tauri.conf.json           # App configuration
├── static/                       # Web-accessible static assets
├── .github/workflows/            # CI/CD release pipeline
├── LICENSE                       # MIT
└── README.md

License

This project is released under the MIT License — see LICENSE for full text.

SPDX-License-Identifier: MIT
Copyright (c) 2026 Brice LECOLE

Name		Name	Last commit message	Last commit date
Latest commit History 101 Commits
.claude		.claude
.github/workflows		.github/workflows
.vscode		.vscode
docs/screenshots		docs/screenshots
scripts		scripts
src-tauri		src-tauri
src		src
static		static
.gitignore		.gitignore
DEV_COMMANDS.md		DEV_COMMANDS.md
LICENSE		LICENSE
README.md		README.md
jsconfig.json		jsconfig.json
package-lock.json		package-lock.json
package.json		package.json
svelte.config.js		svelte.config.js
vite.config.js		vite.config.js

Navigation Menu

Repository files navigation

Hex Studio

Features

File Handling

Hex Viewer

In-Place Editing

Edit Operations

Physical Data View (A2L)

Editing Physical Values

Maps, Cuboids and Cubes

Calibration Data Exchange (CDFX)

Spreadsheet Export

A2L Constructs Supported

Copy Selection to Clipboard

Binary File Comparison (Diff Viewer)

HTML Export — Diff Report

HTML Export — Hex Report

Search & Navigation

Side Panels (View menu or ⌘⇧L / ⌘⇧I)

Preferences (⌘,)

OS File Associations

User Interface

Cross-Platform

Development Toolchain

Getting Started

Prerequisites

Run in development mode

Build a release

Automated releases via GitHub Actions

Project Structure

License

About

Releases

Packages

Contributors

Languages

Folders and files

Latest commit

History

Repository files navigation

Hex Studio

Features

File Handling

Hex Viewer

In-Place Editing

Edit Operations

Physical Data View (A2L)

Editing Physical Values

Maps, Cuboids and Cubes

Calibration Data Exchange (CDFX)

Spreadsheet Export

A2L Constructs Supported

Copy Selection to Clipboard

Binary File Comparison (Diff Viewer)

HTML Export — Diff Report

HTML Export — Hex Report

Search & Navigation

Side Panels (View menu or ⌘⇧L / ⌘⇧I)

Preferences (⌘,)

OS File Associations

User Interface

Cross-Platform

Development Toolchain

Getting Started

Prerequisites

Run in development mode

Build a release

Automated releases via GitHub Actions

Project Structure

License

About

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