Processing boundary
Input is processed only in the active browser tab's memory and is not sent to a ByteQuant server.
102
Text & NLP
Regex Replacement Lab
Runs pattern, flags, and replacement separately, previews capture groups such as $1, and reports matches with before/after output. Input is bounded to reduce catastrophic-backtracking risk.
✓ Free✓ No account✓ In-browser
Persistent storage
Input and output are not stored. The optional usage counter keeps only tool identity and count, never content.
Verification
Output comes from disclosed rules or browser APIs and needs independent review before high-impact use.
A result in three steps
- 01
Enter text, pattern, flags, and replacement.
- 02
Run the bounded preview.
- 03
Check unexpected matches in the before/after view.
When is this tool useful?
- ✓ Drafting bulk renames
- ✓ Reformatting log lines
- ✓ Learning capture groups
Important limitation
Automated output is a preliminary assessment. Do not use it alone for legal, financial, medical, or security-critical decisions.
ABOUT THIS TOOL
Frequently asked questions
Does this tool send input to a server?+
No. Processing runs in this browser tab. Data leaves the page only when you choose to copy or download the result.
Is the result definitive?+
The tool produces consistent output from disclosed rules and browser APIs, but context, data quality, and method limitations can affect it. Verify high-impact decisions.
Is input saved?+
No. Tool input is not persisted. With consent, only tool identity and usage count may be kept on this device for personal shortcuts.