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Binary Data Studio (Hex Viewer)

Drop a file to open it as a hex dump with offsets, hex bytes and a text column. Only the visible rows are read, so even multi-gigabyte files open without freezing, and nothing leaves your device. Search, value interpretation, compare and export are on the same screen.

On-device・No uploadMobile friendlyWorks offline

Your files and input are processed only inside your browser on this device and are never uploaded to our servers.

Drop a file to open it as a hex dump

or

Files never leave your device. Only the visible range is read, on demand.Accepts: Any format, no size limit (opened read-only)Paste (Ctrl+V) also works

How to use

  1. firmware.bin
    firmware_old.bin

    Open a file

  2. Hex dump and search
    Byte compare of 2 files

    Inspect in hex and compare

  3. selection.binselected range only

    Export the chosen range

Open a file in hex, then search, compare and export part of it

  1. Drop a file or click “Choose file”. “Try a sample” loads a sample file plus a second file B for comparison.

  2. Pick the bytes per row (8, 16, 32) and the text column (ASCII, Shift_JIS, UTF-8). Enter an offset (decimal or 0x hex) under “Go to offset” to jump there.

  3. Click a byte, or drag / Shift+arrow to select a range; “Values” shows it as integers, floats, UNIX time and GUID.

  4. “Search” finds hex bytes, text (UTF-8, UTF-16LE, Shift_JIS) or a regex (ASCII only), and lists the matches to jump to.

  5. In “Compare” choose another file to list the differing byte ranges, also highlighted in the dump.

  6. Use “Export” to save the selection as .bin, hex text, a C array or Base64. Small files can be edited and saved as a copy.

What it does

Multi-GB files without freezing

The whole file is never loaded. Only the rows on screen are read, when needed, so huge files open at once. Beyond about 10 million pixels of scroll height the scrollbar is scaled, so use “Go to offset” or the keys to reach the end precisely.

Three text columns

Switch between ASCII, Shift_JIS and UTF-8. A multi-byte character is shown under its first byte and the rest are marked “‥”. Control characters and characters that could disturb the layout show as “.”.

Values at the selection

int8–int64 (signed and unsigned), float32 and float64, UNIX time (seconds and milliseconds, UTC) and GUID, in both little- and big-endian order side by side.

Format hints and entropy

The format (PNG, ZIP, PDF, ELF, PE, SQLite and more) is detected from the first bytes and structure. A graph of up to 256 blocks shows regions that look compressed or encrypted and zero-filled areas; above 256 MB it is an estimate from the first 64 KB of each block.

Byte-level compare and small-file editing

Two files are read in turn and the differing ranges are listed. Editing works on files up to 50 MB: overwrite, insert, delete, undo and redo, and you save a copy — the original file is never changed.

Use cases

  • Check a downloaded file’s real format from its first bytes (magic number)
  • Find exactly where two binaries differ, byte by byte
  • Locate a byte sequence or string inside a custom log or config format
  • Turn part of a firmware image into a C array or Base64 for pasting into code
  • Get a feel for which regions look compressed or encrypted using the entropy graph

Supported formats

Files

Any format (raw bytes shown as hex)No size limit (read-only)Editing up to 50 MB

Search

Hex bytesText (UTF-8, UTF-16LE, Shift_JIS)Regex (ASCII text only)

Export

.bin (selection)Hex textC arrayBase64

Capability matrix

FeatureSupportNotes
Hex dump view (8, 16 or 32 bytes per row)SupportedASCII, Shift_JIS and UTF-8 text columns
Virtual scrolling for huge filesSupportedOnly the visible range is read
Search by hex bytes, text or regexSupportedRegex is ASCII-only and stops after 20 seconds
Value interpretation of the selectionSupportedIntegers, floats, UNIX time, GUID
Byte-level compare of two filesSupportedUp to 5,000 differing ranges are listed
Editing (overwrite, insert, delete, undo)PartialFiles up to 50 MB only; saved as a copy
Export (.bin, hex, C array, Base64)SupportedHex, C array and Base64 up to 4 MB
Editing disks or process memory directlyNot supportedNot possible in a browser; only files you open are handled
Disassembling executablesNot supportedMachine code is not converted to instructions; only format detection and hex display
Overwriting the original fileNot supportedAlways saved as a separate copy

Limits & notes

  • Only files up to 50 MB can be edited. Larger files are read-only, but viewing, search, compare and export still work.
  • One edit operation (insert, delete, overwrite) is limited to 16 MB, and the last 200 operations can be undone.
  • Exporting as hex text, C array or Base64 is limited to a 4 MB selection; .bin can export large ranges.
  • Regex matches one byte as one character, so search Japanese and other multi-byte text with the text type or hex. Matches longer than 512 bytes can be missed, and the search stops after 20 seconds.
  • The match list shows the first 1,000 and the differing ranges the first 5,000.
  • A multi-byte character that starts before the row shows as “.” in the text column. In Shift_JIS, a second byte in the range 0x40–0x7E can look like a letter.
  • Works on phones too, but PC is recommended for comparing or editing large files.

Privacy & safety

Files are never uploaded: your browser reads them directly on your device, and the visible range, search and compare all run locally. File names, contents and search terms are not sent, stored or included in analytics.

FAQ

Can I open a binary file as hex in the browser?
Yes. Drop the file to see a hex dump with offsets, hex bytes and a text column. Nothing is installed or uploaded.
Does it open multi-GB files?
Yes. The file is not loaded into memory; only the rows on screen are read. Search and compare take time depending on your device and can be canceled.
Can I compare two binary files byte by byte?
Choose another file under “Compare” to list the differing byte ranges and jump to each. If the lengths differ, the extra tail of the longer file is shown as one range.
Can I edit and save a file?
Files up to 50 MB can be overwritten, inserted into and deleted from, with undo. Saving never rewrites the original — it downloads a copy. Larger files are read-only.
Can it edit disk or memory, or disassemble executables?
No. A browser cannot touch disks or other processes’ memory, and the tool does not turn machine code into instructions. It detects the format and shows hex.
Japanese text looks garbled. What should I do?
Switch the text column to Shift_JIS or UTF-8. A multi-byte character appears under its first byte. Search also supports UTF-8, UTF-16LE and Shift_JIS text.

File Hash — Checksum Calculator & Verifier

Drop a file to get its SHA-256 (and more); paste the published hash to see match or mismatch instantly. Even multi-gigabyte ISOs are read in chunks on your own device — nothing is uploaded.

No upload

Universal File Inspector

Drop any file to see its real format (from the content), its structure and metadata, what to watch out for, and which tools can process it — before opening it, or before sending it to someone.

No upload

Encode / Decode Studio — Base64, URL, JWT & more

Paste %E3%81%82, an eyJ… token or any encoded string — the format is detected and decoded instantly. Errors say exactly which character is wrong and why, and nothing leaves your browser.

No upload

File Split & Join

Cut a file to a size you choose (around 18 MB suits a 25 MB mail limit), save it as name.ext.001, .002 … and put it back together on the same page. Multi-GB files are read in small pieces on your device, so memory stays flat. Missing or mixed-in parts are reported before joining, and a SHA-256 record confirms the result.

No upload

Date & Time Studio — Unix Timestamp & Time Zone Converter

Paste a Unix timestamp or almost any date string — the unit and format are detected automatically and shown in 15 formats and multiple time zones. DST gaps, month ends and Japanese era boundaries are handled precisely.

No upload

Markdown Studio — Live Editor & Preview

A split-view Markdown editor with instant GFM preview, a table formatter that aligns pipes, an automatic table of contents and HTML export. Output is always sanitized and external images load only when you allow them.

No upload

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