/tools/log-viewer
Local Log Viewer & Analyzer
View, search and analyze NGINX, Apache, JSON, logfmt, syslog or generic logs without uploading them or retaining complete rows in memory.
1. Source
Choose one UTF-8 log file, or paste a small example up to 10 MB.
2. Search and filters
Load a source to filterAdvanced evidence filters
Evidence filters
3. Records
4. Details
Findings
No sampled signals5. Filtered and redacted export
The source stays immutable. Select categories explicitly, or apply the guided sharing-safe policy.
No redaction categories are selected automatically.
/local-report
Sanitisation result
Verification covers the selected deterministic rules; it is not a universal guarantee.
/formats
One online log analyzer for operational formats
Automatic parsing with override
The first 200 nonblank records are scored as structured JSON, logfmt, combined access log, RFC syslog or generic text. Override the parser when domain-specific logs resemble another format.
Bounded random access
The worker reads 1 MiB slices and stores sparse byte checkpoints every 1,024 records. Complete record text is sought only when you inspect it.
Forensic exposure review
Credential, token, cookie and likely-PII rules report masked signals with confidence. Detection does not silently alter display or export data.
Large export path
Supporting browsers stream to a file handle. Other browsers receive a local Blob download capped at 100 MB.
/support
Supported log files and evidence
| Input | Evidence extracted | Example |
|---|---|---|
| NGINX / Apache combined | Timestamp, status, method, path and response bytes | |
| JSON application logs | Nested fields, level, status, request ID and exposure signals | |
| logfmt | Key-value evidence with quoted-value support | |
| RFC syslog | RFC 3164 or 5424 timestamp, host, process and message | |
| Generic UTF-8 text | Searchable rows and masked likely-exposure findings |
The public log fixtures and benchmark method make the supported cases reproducible.
/workflow
Inspect a production log before sharing it
- Choose a log file or load a representative format example.
- Filter by time, status, request ID, level or a bounded regular expression.
- Review masked exposure findings without changing the source.
- Choose explicit redaction categories or the sharing-safe policy.
- Preview and export a local derivative, then review its verification report.
/faq
Online log viewer questions
Does the log viewer upload log files?
No. Indexing, search, inspection and export run locally in browser workers.
Which log formats are detected?
The viewer detects JSON logs, logfmt, NGINX or Apache combined logs, RFC 3164 or 5424 syslog, and generic text. You can override the parser.
Can I search with regular expressions?
Yes. Regex mode is explicit, limited to 512 characters and runs in a disposable worker. A no-progress watchdog can stop it without losing the source index.
Are large records discarded?
No. Records over 8 MB remain countable and exportable, but full display, structural analysis and regex inspection are bounded and reported.