Hex Viewer Online
Drop a file to see every byte as hex and text. A data inspector, find, go to offset and a structure view for 26 formats come with it, free.
Hex Viewer for VS Code and Cursor, free
- Edit bytes: overwrite, insert and delete, with undo and a safe save.
- Open files of 4 GB and more, and compare two files byte by byte.
- A structure view with 26 built-in binary templates, plus your own templates as JSON.
Optional Zovo Pro, USD 19 once: nested template fields with JSON or C struct export, bookmarks, checksums, an entropy map and find in files. 3 free tries for each.
Drop any file here
or
Executables, firmware, images, archives, databases, anything. Large files open at once.
Open this in VS Code or Cursor
The same viewer runs inside VS Code and Cursor, where it also edits bytes, inserts and deletes, compares two files and opens files of many GB.
Free, MIT license. About Hex Viewer for VS Code.
Zovo Pro
Nested fields, compare and export. Zovo Pro, USD 19 once.
In the Hex Viewer extension, Zovo Pro opens every nested field of the structure view with JSON or C struct export, and adds bookmarks with notes, checksums, an entropy map, a compare report and find in many files. Each Pro tool works 3 times without a key. One payment covers the Pro tools in 22 Zovo extensions. Everything that is free stays free.
After a card payment you get a key on the page. With GitHub Sponsors you sign in from the extension. Details on the Zovo Pro page.
Related tools
- Hex Viewer & Binary Viewer on the VS Code Marketplace (also on Open VSX). Opens any file as hex, edits bytes and compares two files, even files of many GB.
- ZIP Viewer & ZIP Explorer. Lists and extracts ZIP, JAR, TAR and GZ archives in VS Code.
- PCAP Viewer & PCAPNG Viewer. Reads packet captures as a table with protocol details.
- NPY, NPZ, PyTorch and GGUF Viewer. Shows tensors, shapes and values from model files.
- SQLite Viewer Online, free in your browser.
- Excel Viewer Online, free in your browser.
- DOCX Viewer Online, free in your browser.
Questions
Is my file uploaded anywhere?
No. The page reads the file with the File API inside this tab. Its Content Security Policy sets connect-src to none, so the page cannot send a request with your data even by mistake. You can check it yourself in the Network tab of your browser tools: opening a file adds no request.
How big a file can it open?
There is no size limit of its own. The page reads only the rows on screen, in 64 KB blocks, so a 50 MB file opens as fast as a small one. Find scans the whole file in 4 MB steps in a background worker and shows its progress.
Which formats does the structure view know?
PNG, JPEG, GIF, BMP, ICO, TIFF, WebP, WAV, FLAC, MP4, ZIP, gzip, TAR, PDF, SQLite, ELF, PE (EXE and DLL), Mach-O, Java class, PCAP, UF2, device tree blobs, uImage, Android boot.img, WebAssembly and DEX. The format is found from the first bytes, not the file name. Click a field to select its bytes.
Can I edit the bytes?
This page only views. The free Hex Viewer extension for VS Code and Cursor edits, inserts and deletes bytes, with undo, and saves large files without loading them whole.
Does it work offline?
Yes. After the first visit the page keeps a copy of its own files, so it opens and works with no connection.
Is a hostile or broken file safe to open?
The page writes file content as plain text, never as HTML, and its policy allows only its own scripts. Templates are data read with limits on fields, depth and time, and they run in a separate worker that stops after 10 seconds.
What is free and what is Zovo Pro?
Everything on this page is free: hex and text view, data inspector, find, go to offset and the top level of the structure view. The nested fields of a structure, the compare report and export are Zovo Pro in the VS Code extension. One USD 19 payment covers the Pro tools in every Zovo extension.