What the Random Fixture Generator helps you do
Use this page to produce bounded fractions, hexadecimal byte groups, base-N strings, ISO date-times, shuffled letters, or text from a deliberately small safe pattern language. The workspace keeps the source, settings, and result together so you can understand what changed instead of receiving an unexplained clipboard value. Start with a small known example before using unfamiliar data.
Pattern [A-Z]{4}\d{2} can produce QJTZ42. Base-N setting 16,12 creates twelve lowercase hexadecimal digits. Byte mode produces sixteen hexadecimal bytes per line. The visible result remains available for selection, copying, and download. Nothing is copied or saved automatically, so you can stop and compare it with the source before taking the next step.
How the conversion works
Unseeded generation draws from the browser’s secure random-byte source. Seeded testing mode uses a deterministic local sequence. Safe patterns are parsed rather than executed as regular expressions and support A-Z, a-z, 0-9, short literal classes, \d, literal safe characters, and fixed {count} repetition.
Select the fixture family first because the input meaning changes with it: base,length for Base-N; source letters for Shuffle; a safe pattern for Pattern. Fractions, bytes, and date-times need no extra input. Inputs and outputs stay in the current browser tab during ordinary use. NexaCurrent does not upload the working value to perform this operation. Reset clears the entered value, settings, result, messages, and generated download from the workspace.
How to use Random Fixture Generator
Enter or paste the smallest complete source value that represents your task. Choose the source format, direction, byte order, output family, or fixture type shown on this page. Run the primary action, read the summary, and inspect the complete visible result before using Copy or Download.
Verify quantity, alphabet, length, range, and format against your test’s actual assertion. Keep the seed with a reproducible test case, but remove it when you want independent random samples. If the receiving application has its own specification, sample, or validator, use that as a second check. A successful result here confirms this page’s stated rules; it cannot promise that another system has selected the same convention.
Errors, boundaries, and recovery
Unsupported pattern tokens, unclosed classes, output expansion above 128 characters, base outside 2–36, invalid length, empty shuffle input, and quantity outside 1–100 are rejected before a result is shown. An error clears an earlier result so an obsolete success cannot be mistaken for the corrected answer. Fix the first message, then run the operation again. Changing the input or a setting also removes stale copy feedback.
Text input is limited to 200,000 characters, generated quantity to 100 items, and pattern or schema expansion to the smaller limits shown beside those controls. These bounds keep one browser tab responsive. For a large file or batch, use a streaming command-line tool and preserve an original copy.
Limits and responsible use
These values are test fixtures. They do not claim statistical sampling quality, uniqueness, identity, ownership, valid allocation, or suitability as passwords, tokens, keys, or production data. Repeatable seeded output is intentionally predictable.
Do not paste a real password, private key, access token, personal record, or production customer dataset when a harmless sample can prove the same behavior. Treat downloaded output as a new file, keep the source until the target system accepts it, and document the selected format whenever another person must reproduce the result.