Intel HEX Viewer & S-Record Viewer for VS Code (HEX, SREC, S19)
Open an Intel HEX or Motorola S-record firmware image in VS Code and see what it puts where in memory: a memory map of the segments, gaps and overlaps, a hex view by address, a data inspector, and every record checked, with the bad lines listed. For .hex, .ihex, .ihx, .srec, .s19, .s28, .s37 and .mot files. Read-only, no network.
What you see
| Tab |
What it shows |
| Overview |
Format and address size, address range, data size, segments and gaps, start address, S0 header text, record counts, checksum result, end-of-file record, line endings |
| Memory map |
Each block of data with its first and last address, size, the gap before it and the lines it comes from; a bar that places the blocks by address; overlapping records marked |
| Problems |
Every line with a wrong checksum, a wrong byte count, a bad hex digit, an unknown record type or a wrong S5/S6 count, with its line number. A click shows the line |
| Hex |
Memory by address, 16 bytes a row, with gaps left empty. Go to an address, step from segment to segment, click a byte to read it in the data inspector (u8 to u64, i8 to i64, float, double, little or big endian) |
| Raw text |
The file itself with line numbers; problem lines are marked |
- Intel HEX: record types 00 to 05, 16-bit, 20-bit (extended segment, 02) and 32-bit (extended linear, 04) addresses, start address records 03 (CS:IP) and 05 (EIP).
- Motorola S-record: S0 header text, S1, S2 and S3 data, S5 and S6 record counts, S7, S8 and S9 start addresses.
- Lowercase digits, CRLF or LF line ends, blank lines and a missing end record are all read. Lines after the end record are reported, not read.
- A file that jumps 2 GB between two records costs only the bytes it holds: gaps are never filled in memory.
- Files of a million lines open in about a second.
Open a file
.srec, .s19, .s28, .s37, .mot, .ihex, .ihx, .h86 and .mcs files open in the viewer when you click them..hex files open as text, because many .hex files hold other things. When a text editor shows Intel HEX or S-records, a board icon appears in the editor title: click it to open the file in the viewer. Or right-click the file in the Explorer and pick Open in Intel HEX Viewer.- Command Palette: Intel HEX Viewer: Open in Intel HEX Viewer.
Free and Pro
Everything above is free, with no limit and no sign-in. Three Zovo Pro tools save time on bigger jobs. Each has 3 free tries on your computer, and a try counts only when the tool gives you a result.
| Tool |
Free |
Zovo Pro |
| Memory map, problems, hex view by address, data inspector, raw text, filter and copy |
yes |
yes |
| Convert: save as Intel HEX, S19, S28 or S37, or a flat binary with the gaps filled; pick the address range and the record size |
3 tries |
yes |
| Compare two images by address: changed byte ranges, data only in one of them, a Markdown report |
3 tries |
yes |
| Checksum or CRC over an address range (CRC-32, CRC-32/MPEG-2, CRC-16/CCITT-FALSE, XMODEM, MODBUS, 8 and 16-bit sums, MD5, SHA-256), and a copy of the file with the value written at an address |
3 tries |
yes |
Zovo Pro is USD 19 once and turns on the Pro tools in every Zovo extension. Nothing about Pro shows when you open a file; it only comes up when you click one of the three tools. To hide the buttons, set intelHex.showProTools to false.
Safe with any file
- The file is read in a separate worker thread with a time and memory limit. A broken or hostile file gives a message and the part that could be read; it cannot freeze VS Code.
- Lines, problems, data size and reading time all have limits, and the viewer says when one was reached.
- Read-only: the extension never changes the file you opened. Convert and Checksum write new files only where you pick.
- No network and no telemetry.
Commands
| Command |
What it does |
| Intel HEX Viewer: Open in Intel HEX Viewer |
Open a file (also in the Explorer right-click menu and the editor title) |
| Intel HEX Viewer: Open a sample Intel HEX file |
A small sample to try the viewer |
| Intel HEX Viewer: Convert to Intel HEX, S-record or binary (Pro) |
Save the image in another format |
| Intel HEX Viewer: Compare two firmware images (Pro) |
What changed between two builds |
| Intel HEX Viewer: Checksum or CRC over an address range (Pro) |
Compute a value and write it into a copy |
Settings
| Setting |
Default |
|
intelHex.showProTools |
true |
Show the Convert, Compare and Checksum buttons |
intelHex.showSupportLinks |
true |
Show the small links at the bottom of the viewer |
intelHex.askForRating |
true |
Ask once, after a few days, whether you want to rate it |
Limits
- Plain
.bin files are not read here. Hex Viewer opens them.
- Text files up to 256 MB (about 6 million lines). The Problems tab keeps the first 10,000 problems and counts the rest.
- No disassembly and no editing in place.
- The viewer checked its reader and converter against GNU objcopy and llvm-objcopy on real firmware images.
Works in VS Code 1.90 and later, Cursor, Windsurf and VSCodium.
Support Zovo
Zovo Pro: USD 19 once, every Zovo viewer. Get Zovo Pro on GitHub Sponsors to turn on the Pro tools in this extension and in the other Zovo extensions you use. The free features stay free.
Zovo extensions have no ads and no tracking. They are made by theluckystrike on GitHub. You can also support the work with no Pro:
Open a format request with a sample file, and I reply there whether it can be done. For USD 299 once, through this GitHub Sponsors tier, I add your file format or a missing feature to this extension, with tests, within 7 days.
- VCD Viewer & Waveform Viewer (Verilog, No Signal Limit) opens Verilog, SystemVerilog and VHDL VCD waveforms with no signal limit.
- Linker Map Viewer & Map File Analyzer (GNU ld, Memory Usage) shows FLASH and RAM use from GNU ld, lld, IAR and Keil map files.
- PCAP Viewer & PCAPNG Viewer (Packet Capture Analyzer) opens PCAP and PCAPNG captures with a packet list, filters and a hex pane.
- Hex Viewer & Binary Viewer, Hex Editor (Large Files) opens binary files of any size, with find, a data inspector and byte editing.
- Run C++ and C Code: One-Click Compile with GCC, G++, Clang (CPP Runner, Input Panel) compiles and runs the current C or C++ file with gcc or clang.
See all Zovo extensions on the Marketplace.
| |
