What UwView Pro is
UwView Pro is a desktop viewer for enormous text and log files. It opens files of tens of gigabytes — the developer's benchmark file is a 47.73 GB, 892-million-line OSM dataset — and lets you read, scroll and search the whole file from the moment it opens. Indexing and a compressed cache are built in the background, so the middle and end of the file are reachable immediately instead of being blocked until indexing finishes.
Why it stands out
- Instant on every open. The index and compression are saved to a
.uwvzsidecar, so the second open onward takes roughly 0.02–0.07 s with line numbers already available. - Faster search. Searching through the compressed cache measured about 9× faster for literal / case-insensitive queries and about 4.4× for regex, with hit counts matching the comparison tool exactly.
- 1/9 archiving. A log can be archived at roughly one-ninth of its size (48 GB → 5.3 GB, checksum-protected) and opened directly without extracting.
- Non-destructive editing (Edit Upgrade). Fixes and mass replacements accumulate in a sidecar diff (
.ewvz) while the original file stays untouched, so a one-line fix in a 100 GB file is instant and a job can be paused and resumed later.
Everyday features
Color highlighting with right-click colorize and exportable presets, search history and saved filters, rectangular block selection for fixed-width logs, session restore with recent files and favorites, drill-down and sequence search for narrowing large hit sets, Japanese encoding auto-detection (Shift-JIS / EUC-JP), and an English / Japanese UI.
Platforms and licensing
Available for Windows 10/11 (x64 / ARM64), macOS 11+ (Apple Silicon / Intel, notarized), and Linux (x86_64 / ARM64). The View License is $129 one-time or $9/month; the Edit Upgrade adds $120 one-time or $8/month and requires a View License. Every license starts with a full-featured 14-day trial. A free edition, UwView, also opens huge files instantly and includes real-time Tail, which Pro does not have.