PDF String Obfuscator
Obfuscate PDF strings using four powerful techniques — hex encoding, escape sequences, font encoding tricks, and CMap character mapping. Enter any text and get PDF-compatible obfuscated string representations. All methods generate valid PDF output. Free, private, and no signup required.
Obfuscate PDF strings using four powerful techniques: hex encoding for hexadecimal string literals, escape sequences for PDF literal strings with backslash codes, font encoding tricks with custom /Encoding dictionaries and /Differences arrays, and CMap character mapping with bfrange/bfchar operators. Each method generates valid PDF-compatible output. Compare all methods side by side or focus on one.
Enter text above to obfuscate it using 4 PDF string techniques: hex encoding, escape sequences, font encoding tricks, or CMap character mapping. Click any example below the input to get started.
Powerful PDF String Obfuscation
Obfuscate PDF strings using four powerful techniques — hex encoding, escape sequences, font encoding tricks, and CMap character mapping — all running entirely in your browser.
PDF Hex Encoding
Encode strings as PDF hexadecimal string literals using the <hexdigits> format. Each character is converted to its two-digit hex code and wrapped in angle brackets, producing strings like <48656C6C6F> that PDF renderers decode natively.
Escape Sequence Support
Generate PDF literal string objects with backslash escape sequences including \n, \r, \t, \f, \\, \(, \), and octal character codes (\ddd). Creates strings like (Hello\nWorld) that PDF interpreters process with full escape resolution.
Font Encoding Tricks
Apply font encoding-based obfuscation by generating /Encoding and /Differences entries that remap character codes. Creates custom font encoding vectors that reassign glyphs to non-standard positions while keeping the text visually correct.
CMap Character Mapping
Generate CMap (Character Map) stream objects that define custom character-to-glyph mappings using bfrange and bfchar operators. Maps character codes to different Unicode values, producing text that displays correctly but has different underlying character codes.
Common Use Cases
The PDF String Obfuscator is used by document security professionals, PDF developers, educators, and content protection specialists worldwide.
Protect Sensitive PDF Content
Obfuscate strings in PDF documents that contain sensitive information like names, addresses, or account numbers. Hex encoding and CMap mapping make the raw string data unreadable in the PDF source while displaying correctly to users.
Digital Rights Management
Encode license keys, activation codes, and DRM-related strings in PDF documents using layered obfuscation techniques. Combine hex encoding with font encoding tricks to create multi-layer protection that resists casual extraction.
Document Forensics Testing
Security researchers and PDF analysts can generate obfuscated PDF strings to test document analysis tools, string extractors, and PDF parsers. Validate how well security scanners detect and decode obfuscated PDF content.
Financial Document Security
Protect financial PDF documents by obfuscating transaction details, account numbers, and personal identifiers within the PDF structure. CMap mapping ensures correct visual display while hiding the underlying character data.
Educational & Research Use
Educators teaching PDF security, document forensics, and reverse engineering can use this tool to demonstrate PDF string obfuscation techniques. Compare all four methods side by side to understand their strengths and weaknesses.
PDF Anti-Tampering Protection
Obfuscate strings that perform integrity checks or validation logic within PDF documents. Font encoding tricks and escape sequences make it harder for attackers to locate and modify security-critical string content.
About PDF String Obfuscation
Understand the four PDF string obfuscation techniques — hex encoding, escape sequences, font encoding tricks, and CMap character mapping — and how they protect string content.
What Is PDF String Obfuscation?
PDF string obfuscation is the practice of encoding or transforming text strings within a PDF document so that the raw string data in the PDF source is not immediately readable, while the document still displays correctly to users. PDF supports multiple string formats including literal strings (in parentheses) and hexadecimal strings (in angle brackets), each with escape sequences and encoding options that can be used for obfuscation.
Hex Encoding vs Escape Sequences
PDF hexadecimal strings use the format <48656C6C6F> where each pair of hex digits represents one character. This is the simplest obfuscation method and is natively supported by all PDF readers. Escape sequences in PDF literal strings use backslash-prefixed codes like \n for newline, \r for carriage return, \( and \) for parentheses, \\ for backslash, and octal codes like \101 for the letter A. These escapes are processed during PDF interpretation and are transparent to the end user.
Font Encoding and /Differences
PDF fonts can define custom character encodings using the /Encoding dictionary and /Differences array. By specifying a base encoding (like WinAnsiEncoding or MacRomanEncoding) and then overriding individual character codes with /Differences, text that uses different underlying character codes can still display as expected. This technique remaps character codes from their standard positions to non-standard ones, effectively obfuscating the string data at the encoding level.
CMap Character Mapping Technology
CMap (Character Map) files in PDF define mappings from character codes to CIDs (Character Identifiers) or Unicode values. Using bfrange (range-based mapping) and bfchar (individual character mapping) operators, a CMap can remap entire character code ranges. This is the most powerful obfuscation technique — the underlying character codes differ completely from the displayed text, making extraction and analysis significantly harder without access to the CMap.
Frequently Asked Questions
Everything you need to know about PDF string obfuscation techniques.
PDF string obfuscation is the process of encoding text strings within a PDF document so they are not immediately readable when viewing the raw PDF source. The text still displays correctly to users but appears as encoded data (hex, escaped, or remapped character codes) when examined directly. This protects sensitive string content from casual extraction.
PDF hexadecimal strings are written between angle brackets, with each character represented by its two-digit hexadecimal code. For example, the string "Hello" becomes <48656C6C6F>. PDF readers decode hex strings automatically when rendering. This is the simplest method and is fully compatible with all PDF specifications.
PDF literal strings (enclosed in parentheses) support these backslash escape sequences: \n (newline), \r (carriage return), \t (horizontal tab), \f (form feed), \\ (backslash), \( (left parenthesis), \) (right parenthesis), and \ddd (octal character code up to \777). These escapes are processed during PDF interpretation, making the display identical to unescaped text.
Font encoding tricks work by creating a custom /Encoding dictionary in a PDF font with a /Differences array that remaps character codes. For example, by specifying differences that map code 65 (normally A) to code 90 (normally Z), text that appears as "Hello" in the PDF source would display as "Hello" only if the font encoding correctly maps those codes. This technique obfuscates at the encoding level rather than the string level.
A CMap (Character Map) is a PDF stream object that defines mappings from input character codes to output CIDs (Character Identifiers) or Unicode values. It uses operators like bfrange (for mapping contiguous code ranges) and bfchar (for mapping individual characters). CMap-based obfuscation is the most powerful technique as it completely redefines the character-to-glyph mapping independently of standard encodings.
Yes, all four obfuscation methods produce valid PDF string representations. Hex encoding and escape sequences use standard PDF literal and hexadecimal string syntax. Font encoding tricks and CMap mapping use standard PDF font and CMap dictionary structures. The output can be directly embedded in PDF content streams or string objects.
Absolutely. All obfuscation processing runs entirely in your browser. Your text input and generated PDF strings are never sent to any server, stored, or tracked. Everything stays on your device for complete privacy.
No, this tool obfuscates individual text strings intended for use in PDF documents. It does not parse, modify, or generate PDF files. You copy the obfuscated string output and embed it in your PDF content streams, font dictionaries, or CMap streams using your PDF generation workflow.
Yes, 100% free with no signup, no account, and no usage limits. Obfuscate as many strings as you need using all four techniques. All features including copy, download, and example presets are available without restrictions.