FasView — Image Viewer

FasView is a native Windows image viewer and file browser: a single portable executable that views images at full quality and organizes them with one-click filing tools. No installer. No account. No subscription. No Internet connection. No AI.

It was built because the good image tools disappeared. The fast, obvious viewers of the early 2000s, the ones people used for 25 years, didn't get upgraded. They morphed into subscription platforms, cloud services, and AI-driven catalogs that demand logins, upload your photos, and keep getting harder to use for the basic things they used to do well.

FasView is the answer to a simple question: what if someone just built the good tool again, modernized it, and shared it freely?

This manual describes what FasView does, how it works under the hood, what problems it solves, and why it is designed to still work ten years from now.

2.1 The market left users behind

Modern photo software has converged on a model that serves companies, not people:

• Subscriptions: you rent access to your own photos, forever.
• Cloud accounts: your pictures upload to someone else's servers by default.
• AI cataloging: algorithms decide what your photos mean, tag faces, and build profiles.
• Bloat: simple tasks (view, sort, rename, file) buried under features nobody asked for.

Each of these is a compromise the user never chose. Nobody woke up wanting their image viewer to require a login.

2.2 The disorganized user

A huge number of people have the same problem: folders and files everywhere, and somewhere along the way, maybe ten years ago while backing something up, they lost track of where anything is. Pictures scattered across drives, old backup folders, desktops, downloads, nested folders inside folders.

This is not an edge case. It is one of the most common states a personal photo collection can be in. And the existing tools are terrible at fixing it, because they want to import everything into a proprietary catalog rather than help you organize the files you already have.

2.3 What photographs are worth

Pictures are among the highest-value things people own. The house-fire anecdote is real: people rush back in for the family photos. A tool that organizes and protects them has value that is hard to estimate. It should be trustworthy, simple, and permanent, not a service that can change its terms, raise its price, or shut down.

3.1 The person decides, the tool obeys

Every consequential action in FasView is initiated by the user. Nothing auto-organizes. Nothing auto-tags. Nothing uploads. The tool never force-checks a preference, never overrides a choice, and never surprises the user with a renamed file or a moved photo. Filing is always one click or one keypress. Never a menu dive, never a confirmation gauntlet.

3.2 Robustness over speed

Large file operations take time and resources. That is expected behavior, not a bug. FasView is designed to handle large operations solidly:

• Honesty upfront: if an operation will take hours, it says so before starting, with real numbers.
• Progress along the way: continuous, cancellable, never silent.
• Crash vs. slow: the user can always tell whether the tool is working, stuck, or dead.

Speed is a design principle, not a benchmark: small moves should feel instant, and long operations must say so plainly instead of looking frozen. Tested with large real collections, including 1.2M images loaded in user testing (October 2026). As the author puts it: "We'd rather be in a car that gets us there than one that tries to get us there fast and breaks down."

3.3 The promise

• Not a hard learning curve.
• Portable: copy it, run it, no installer.
• Doesn't cost money. Get it once; no buying it again next year.
• Doesn't connect to things you don't understand that collect data on you.
• Doesn't spy on you.
• No AI deciding things for you: you choose what stays, what goes, and where it belongs.
• Doesn't nag you. Doesn't throttle you.

3.4 Built for ten years

FasView v1 must be solid and usable for the next decade. That means: no server dependencies that can shut down, no file formats that require a cloud service to decode, no features that stop working when a subscription lapses. A portable EXE on a USB stick, in 2036, should still view and organize photos exactly as it does today.

4.1 Stack

The application is split into two assemblies: FastImageViewer.Core (platform-independent logic: file enumeration, duplicate analysis, policies) and FastImageViewer.App (Avalonia UI). Windows-specific operations (Recycle Bin, file associations) live behind small interfaces in a Windows adapter assembly. This separation is what makes a future Linux port feasible without rewriting the application.

4.2 Viewing pipeline

Images load on background threads with stale-request protection, so scrolling fast through thousands of thumbnails never shows the wrong image. The requested image displays before folder enumeration completes; thumbnails generate progressively with bounded caches and queues. Image streams are never held locked after loading. Viewing never modifies files.

Display rotation (including EXIF auto-orientation) is applied at render time and never touches the file. File rotation (JPEG lossless EXIF flip, PNG pixel rewrite) is a separate explicit action with confirmation.

4.3 Filing engine

All file operations (Copy, Move, Archive, Rename, Recycle, Delete, Destroy) run through a single filing pipeline:

1. Destination resolution: remembered last destination, recent-folder list, or explicit picker.
2. Conflict detection: per-file comparison (name, size, content hash) with visual side-by-side review.
3. Execution: cancellable, with throttled progress reporting (UI updates ~7×/second, not per-file, so 7,000-file operations don't stutter).
4. Completion reporting: status bar summary that survives the post-operation auto-refresh; optional results dialog.

No operation silently overwrites. "Keep both" generates unused names. "Skip when identical" compares contents, not just names.

4.4 Combined folders

Multiple folders (optionally with subfolders) merge into a single virtual view. The implementation:

• Each folder is enumerated independently on background threads; results stream into a unified sorted list.
• Well-known Windows system locations (Windows, Program Files, ProgramData) are skipped automatically during recursive scans; explicitly added folders are always honored.
• A combined view of large collections (tested to 1.2M images, October 2026) loads, sorts, and scrolls without degradation.
• The Details view gains a sortable Folder column showing each file's source; the file tree stays navigable.
• Auto-refresh is always on: filesystem watcher events reconcile the view rather than letting it go stale.

4.5 Duplicate detection

Two-phase, designed for collections up to hundreds of thousands of files:

1. Size grouping (instant): files are grouped by byte size; files with unique sizes are eliminated without reading a single byte.
2. Quick scan: candidates are fingerprinted by hashing the first and last 64 KB. Four files hash concurrently.
3. Full verify: candidate groups are confirmed by full-content SHA-256, four concurrent.

Before the heavy phase on large collections (10,000+ candidates), FasView shows the real numbers (candidate count, data volume, and a time estimate) with a Cancel option. Every phase is cancellable, reports live progress with ETA, and skips unreadable files (bad sectors, stalled drives) instead of hanging. Verification never deletes anything; it selects likely redundant copies and leaves at least one file unselected per group for human review.

4.6 Batch rename

The Rename series engine applies templates with a small placeholder language:

• #: sequence number, zero-padded to the number of # characters (#### → 0001)
• *: original filename without extension
• {date} / {time}: file date/time in ISO 8601 basic format (20241007, 143022)
• {event} / {location} / {desc}: batch metadata, auto-sanitized for filenames

Metadata fields follow IPTC photo-metadata naming (Headline, Location, Description), so generated filenames like 20241007_sarahs_birthday_yosemite_001.jpg parse cleanly into database columns later. Optional archival sanitizing (spaces→underscores, lowercase) produces fully archival-safe names. A live preview shows every old→new mapping with collision warnings before anything is renamed.

4.7 Secure deletion

Destroy goes beyond OS deletion: it renames the file to a random name first, overwrites its contents with one pass of cryptographically random data, verifies each chunk by reading it back, then deletes it. It refuses to run on compressed, encrypted, hard-linked, cloud-synced, or removable volumes, and says why. On solid-state drives (SSDs), it warns before running: the drive's wear leveling can write the new data to different physical cells, so the original data may survive. For sensitive files on an SSD, full-disk encryption (BitLocker) is the reliable protection.

5.1 Viewing

Thumbnails, Details, fullscreen, and slideshow modes. Shrink-to-fit and enlarge-to-fit as independent toggles. Display rotation including auto-portrait. Zoom with lock. Sideways-monitor support. HEIC/HEIF decode with one-click high-quality JPEG conversion. Multi-layer PSD viewing. Every supported format renders through the same pipeline.

5.2 One-click filing

While viewing, file the current photo without breaking flow:

• Archive slots (A–E): five configurable destinations (up to 26), each Copy or Move. The A key files to the first slot; Alt plus a slot's letter files straight to that slot. Slots are lettered A, B, C by default, and you can relabel them with any single character.
• Ratings: number keys file into auto-created numbered subfolders. Triage thousands of images at keyboard speed. Configurable from 2 to 10 ratings, Move or Copy.
• Copy To / Move To: remembered destinations, recent list, typed paths.

5.3 Visual triage: human judgment at speed

Ratings solve a class of problems that expensive AI-driven tools don't: decisions only a human can make, at volume.

• Yay or nay: casting headshots for a role, models for an ad campaign. Set 2 ratings. First pass: tap 1 for yes, 2 for no. Hundreds of candidates sorted in minutes.
• Graded quality: 5 or 10 levels for nuanced judgment, such as portfolio curation, contest entries, and product shots. The folder structure becomes the score.
• Database feed: the numbered folders are machine-readable. Downstream, a database or spreadsheet can rank candidates by folder, combining human judgment with other data. The tool collects the decisions; the human makes them.

No AI can look at a headshot and know if the person is right for the part. That is the point. FasView makes the human fast instead of replacing them.

5.4 Organizing scattered collections

The rescue workflow for disorganized archives:

1. Combine: point combined folders at the mess; every image appears in one view.
2. Group: sort by the Folder column to see which files came from where.
3. Select: right-click → "Select all from this folder" grabs every file from one location in one step.
4. File: archive slots, ratings, or Copy/Move into the organized destination.
5. Dedupe: Find dupes catches the copies accumulated across years of haphazard backups.
6. Name: Rename series with batch metadata produces consistent, database-ready filenames.

5.5 What it doesn't do

No catalog database. No import step. No face recognition. No cloud sync. No AI tagging. No account. Files stay where the user puts them, named what the user names them.

FasView is the antithesis of the subscription-based, web-connected, AI-driven, expensive image tool. It does the job the 2000s classics did (viewing, sorting, organizing), modernized, and without everything that got bolted on since.

A tool for irreplaceable possessions must outlive business models. FasView's survival design:

• No servers: nothing to shut down, no API to deprecate.
• No activation: no license server to go dark.
• Standard formats: reads and writes files any tool can open; no proprietary catalog to become unreadable.
• Portable: a single EXE. Copy it to a USB stick, an archive drive, a new PC in 2036. It runs.
• Offline-first: every feature works with no network. Airplane mode is a feature, not a limitation.
• Human-readable output: archival filenames (ISO 8601 dates, IPTC-aligned metadata) remain meaningful without any software at all.

The goal: in ten years, this exact binary still views and organizes photos exactly as it does today.

FasView is shared freely. No login, no license key, no registration. That is the whole idea. The portable executable is the distribution: download it, run it, copy it for a friend.

The author is not in it to make a lot of money. The tool exists because the good ones disappeared into subscriptions and bloat, and somebody should just make the good one and share it.

FasView: the car that gets you there.