String Obfuscator
TextObfuscate text by replacing middle characters with asterisks for emails, phones and credit cards to protect sensitive data in logs, tickets and screenshots.
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About String Obfuscator
When taking demo screenshots, writing docs, or sharing logs, sensitive values like emails, phone numbers, card numbers, and tokens must be masked — yet you often want to keep a few leading and trailing characters so readers can still recognize the format. This tool masks strings locally in your browser: you choose how many characters to keep at the start and end, and the middle is replaced with a customizable symbol (asterisk by default). Built-in email, phone, and card presets bring common keep-rules one click away. Keep in mind an important boundary: masking that uses a literal symbol is irreversible, so preserve your original data before batch-processing. For fully reversible display obfuscation you can use the light encoding mode and restore it later. This is about readability and accidental exposure, not cryptography — it raises the friction for copying real values but does not withstand deliberate reverse engineering. Everything runs on-device and nothing is uploaded.
How to Use
- Open the String Obfuscator tool
- Paste the text to process
- Adjust the output options as needed
- Click the Process button; results appear in real time
- Copy or export the result
Use Cases
- Screenshot redaction — Turn a phone number into 138****5678 before capturing, hiding the real digits.
- Doc examples — Show card format in API docs, keeping the first and last four for reference.
- Sharing logs — Mask the middle of emails or tokens before pasting into a forum for help.
- Support tickets — Partially mask user accounts in tickets to balance recognition and privacy.
- Quick presets — Apply common keep-rules instantly with the phone and card presets.
- Mask test data — Obfuscate real-looking test data in seed scripts so they are safe to commit to shared repos.
- Redact CI output — Mask secrets or personal data in CI pipeline logs before sharing build output for debugging.
FAQ
Can masked text be reversed?
No. Masking permanently replaces the middle characters with symbols and is irreversible, so keep a copy of the original.
What if the kept counts exceed the length?
When the kept start and end characters cover the whole string, there is no middle to mask, and the tool returns the input unchanged.
Can I change the asterisk?
Yes. The mask character is customizable — use # or • to match your document style.
Does it mask emails intelligently?
It masks by character position and does not parse email structure. To normalize email format, use our Email Normalizer.
Does it handle CJK or emoji correctly?
It works per character; regular CJK masks fine, but some multi-codepoint emoji may split, so prefer plain-text identifiers.
Is obfuscation the same as encryption?
No. Obfuscation only lowers readability for display and is reversible and easy to crack; encryption requires a key and cannot be undone without it. Their purposes and security are very different.