# Check barcode scanner prefixes, suffixes and hidden characters

https://scannerbench.smartfact.ai/barcode-scanner-prefix-suffix/

Spaces, prefixes, terminator keys and invisible characters can be easy to miss. Inspect the captured value and test an explicit comparison rule without losing the original.

For developers and support teams matching scanner input to order numbers, location codes or known test payloads.

## Keep exact comparison visible

An exact mismatch is evidence. ScannerBench shows it even when a configured comparison rule produces a match. You can remove a literal prefix or suffix, trim outer ASCII spaces or convert CRLF to LF in the comparison view. Rules apply in the order you select, only to the selected observation.

## How to use ScannerBench

1. **Capture a known value.** Start with a barcode whose encoded text is independently known. Inspect the escaped text and Unicode character list before adding any transformation.
2. **Distinguish text from keys.** Look at received characters and the event log separately. Enter and Tab may finish capture without becoming text. A Ctrl+] event alone does not establish that U+001D reached the field.
3. **Try one explicit rule.** Add only the rule you want to investigate. Compare the original exact result and the configured result, then include the observation in a reviewed report.

## A trailing space is still a character

The strings ABC-0017 and ABC-0017 followed by U+0020 are different. An outer-space rule can demonstrate that the space explains a mismatch, while the original capture remains unchanged. This does not change the scanner or fix the receiving application.

## Questions

### Can it show a GS separator?

If the browser field receives U+001D, the inspector names it as GS. Literal backslash-u text is a different value. The current tool does not parse or validate GS1 element strings.

### Are CR and LF preserved exactly?

Browser textareas normalize line endings. Available paste-event text is retained separately from field text, and imported expectations retain their strings. Choose the observation carefully when comparing line endings.

### Will my next scan be silently corrected?

No. Comparison rules do not rewrite stored captures or program the scanner. Exact and configured outcomes stay separate.

## Current scope

Capture text from scanners that behave as a native keyboard. Inspect characters and browser key events, compare a known value, import shared test expectations and download a reviewed report. Enter, Tab, manual finish and opt-in idle completion are available.

This is a software-tested alpha. Physical scanner and OS combinations are not yet qualified. Model selection provides reviewed manual references; it does not detect, configure or certify a scanner. Raw HID, serial input, camera scanning, barcode decoding and GS1 interpretation are outside this release.

## Privacy

Scan values, expectations and device notes are processed in browser memory. No account, upload or tracking scripts are required. Reloading loses the session. Reports are redacted by default and downloaded only after review. Hosting may log ordinary page requests; suite links contain only a fixed referral marker.

[Open ScannerBench](https://scannerbench.smartfact.ai/)