Strings Extractor
Extract printable strings from binary files in your browser. ASCII + UTF-16LE, byte offsets, regex filtering, and CTF flag-pattern detection.
Drop any binary file here or click to browse
EXE, ELF, firmware, images, archives — any format · Max 50 MB
Scanned entirely in a background WebWorker — nothing uploaded
100% Client-Side · WebWorker Processed · Up to 50 MB
All string extraction runs in a background WebWorker — the page stays responsive even on large files. Nothing is sent to a server.
How to extract strings (4 steps)
- Upload a File: Drop any binary — executable, image, archive, or unknown file up to 50 MB. Nothing leaves your browser.
- Wait for the Scan: The tool scans for printable ASCII and (optionally) UTF-16LE strings in a background WebWorker so the page stays responsive.
- Review Flag Matches: Any string matching a common CTF flag pattern (flag{...}, HTB{...}, picoCTF{...}, etc.) is highlighted at the top.
- Filter & Copy: Type a keyword to filter results. Copy individual strings or all currently filtered results with one click.
Frequently Asked Questions
What file types are supported?
Any file up to 50 MB. The tool reads raw bytes — format does not matter. Works on executables, images, archives, unknown blobs, and anything else.
Does the file get uploaded anywhere?
No. Scanning happens entirely in a WebWorker inside your browser. No data is sent to any server.
What is the minimum string length?
Default is 4 characters — the same as the classic 'strings' utility. CTF mode raises this to 6 to reduce noise.
What flag patterns are detected?
flag{}, ctf{}, HTB{}, THM{}, picoCTF{}, and the generic <word>{...} pattern used by most CTF platforms. Patterns are case-insensitive.
What is UTF-16LE scanning?
Windows executables often store strings as UTF-16LE (two bytes per character with a zero byte between). Enable this option to catch strings that ASCII scanning would miss.
Why do I see so many results?
Binary files contain many byte sequences that look like printable text. Use the filter box to search for specific keywords, or increase the minimum length to reduce noise.
What does 'Copy All' copy?
Copy All copies only the currently filtered results — if you have a filter active, only matching strings are copied. This lets you quickly export a focused subset.
ASCII vs UTF-16LE strings
The two encoding types this tool searches for — and when to use each.
| Property | ASCII | UTF-16LE |
|---|---|---|
| Bytes per character | 1 byte | 2 bytes (null between) |
| Common in | Linux/Unix ELF, scripts, configs, most CTF files | Windows PE/DLL, Word .docx, Registry exports |
| Example bytes | 68 65 6C 6C 6F (hello) | 68 00 65 00 6C 00 6C 00 6F 00 |
| Default mode | Always enabled | Enable with UTF-16LE toggle |
| CLI equivalent | strings (default) | strings -el |
| When to enable | Always (default — never disable) | Target is a Windows binary or Office file |
Other tools in your CTF workflow
Strings extraction is usually step 2. Use these tools before and after.
Magic Byte Detector
Identify the real file format from header bytes — before extracting strings
Steganography Analyzer
Run entropy and chi-square analysis on images that strings can't decode
Binary Steganography Extractor
Extract payloads hidden in binary files using BINSTEG methods
Hex Viewer
Browse raw bytes and see the hex offset alongside strings
Metadata Extractor Soon
Pull EXIF, XMP, and embedded metadata — often contains flags
Embedded File Scanner Soon
Detect files hidden inside files (polyglots, appended payloads)