DATA / DOCUMENTS / BOOKS / IMAGES
File Viewer — Drop Any File, Opened Instantly in Your Browser
Your file is detected automatically and opened locally in your browser. Nothing is uploaded, no account needed.
ViewerHub is a free file viewer for the supported formats below. Choose a local file to inspect data, read a document or explore a book. Opening time depends on the file and available memory; unsupported or damaged files may not open.
Online page, local processing →Drop a file here
Data, documents, ebooks, images, maps or 3D models.
Your files stay on your device.
Supported formats
Each format opens with tools suited to its contents. Follow a format link for detailed instructions and compatibility notes before choosing a large or unfamiliar file.
| Format | What you can do |
|---|---|
| CSV | Search, filter, sort and export the current page of rows. Delimiter and header controls keep values as strings, including leading zeros. |
| TSV | Browse a virtual table, search all rows, sort columns and export the current page as CSV. Tab is the default delimiter. |
| JSON | Read the source, expand a tree, search source lines or explore arrays of records as a table. Download the original bytes at any time. |
| JSONL | Read source and trees, browse object records in a table and find invalid JSON by line number. NDJSON is also supported. |
| Parquet | Inspect schema and row counts, search, filter and sort using local DuckDB-Wasm. Export the current page as CSV. |
| XML | View attributes, namespaces and ordered text in a read-only tree. Search the source and download the original file. |
| YAML | Inspect multiple YAML documents, search source lines and preserve scalar spelling. Aliases are shown without expansion. |
| EPUB | Navigate chapters, adjust text size and background, and bookmark chapters for the current session. Bundled raster images are supported. |
| HEIC | Decode a primary still image on your device, rotate the preview and export JPG or PNG. Processing stays local, including the fallback decoder. |
| Navigate pages, zoom, fit to width, select extracted page text and search the document. Enter supported PDF passwords locally. | |
| DOCX | Read main-body paragraphs, headings, bold text and basic tables in a sanitized, sandboxed HTML frame. No editing or Word installation required. |
| XLSX | Switch visible worksheets; search, filter and sort bounded cell tables. Read cached formula values and export the current table page as CSV. |
| PSD | Preview the saved flattened composite; zoom, rotate and export PNG or JPG. No layer editing or layer rendering. |
| SQLite | Read-only user table picker, column types, row counts, search, filter, sort and current-page CSV export. BLOB values show byte counts. |
| GeoJSON | Local SVG sketch of points, lines and polygon outlines, feature counts and paged property inspection. No remote map tiles or user content sent to mapping services. |
| KML | Local SVG sketch of points, lines and polygon outlines, feature counts and paged property inspection. No remote map tiles or user content sent to mapping services. |
| STL | Static triangle geometry with orbit, zoom, pan and camera reset. Neutral shading; scene transforms are applied and model scale is normalized for display. |
| GLB | Static triangle geometry with orbit, zoom, pan and camera reset. Neutral shading; scene transforms are applied and model scale is normalized for display. |
| GLTF | Static triangle geometry with orbit, zoom, pan and camera reset. Neutral shading; scene transforms are applied and model scale is normalized for display. |
| OBJ | Static triangle geometry with orbit, zoom, pan and camera reset. Neutral shading; scene transforms are applied and model scale is normalized for display. |
Automatic detection, on your device
You do not need to pick a reader before opening a supported file. The detector reads a small sample of bytes, checks known binary signatures and text patterns, and considers the filename extension. PDF and Parquet have recognizable signatures; delimited and structured text can be less definite. If several text formats match, the workspace asks you which reader to use.
Detection identifies a likely format, rather than proving that every part of the file is valid. The appropriate parser checks the contents as it opens them. Once a format is selected, the workspace shows a Detected message with a link to its public guide. A file with the wrong extension, unsupported codec or damaged structure can still be rejected. Your file stays local throughout these checks.
How it works
- Choose or drop a file. Use the button above or drop a file from your device. If you drop several files, select one from the list. No account, subscription or file upload is needed.
- Let the browser find the reader. Detection runs locally, then the workspace opens the matching tools. For ambiguous text, choose a format when prompted. Large files can take longer, and you can cancel opening or replace the file.
- Inspect and keep what you need. Read pages or chapters, inspect structured text, or search and filter table records. Available controls depend on the format. Download the unchanged original or use a supported export; table CSV exports contain only the current page.
Choose tools that fit the file
A table is useful for comparing rows, while a tree helps you follow nested records. Books and documents need chapter or page navigation instead. ViewerHub brings these reading tasks into one workspace without asking you to import a library or set up a database. It does not replace a spreadsheet editor, a full data conversion tool or a document authoring application.
For analytical data, start with how to open a Parquet file and the current-page CSV export guide. For books on a PC, the Windows EPUB reading guide explains the supported reading mode. The complete capabilities directory compares size limits and restrictions across all readers.
Local processing and practical limits
The website delivers its interface and engine assets over the network. Selected file bytes are processed in your browser, with no upload or cloud fallback. Closing or reloading the tab clears the file session, including session bookmarks. Files you deliberately download remain on your device. Read the privacy notes for the boundary between loading a website and processing a file.
Input caps are safeguards, not promises that every file below the limit will open. Compressed data can expand substantially, and browser memory, codecs and document structure affect results. A recent browser with WebAssembly and workers is needed. First-visit offline use is not supported. If opening fails, check the format guide and try a smaller supported file rather than expecting a server to finish the job.
File viewer FAQ
Is this really online?
Yes. The page is online, but file processing stays in your browser with no upload. The website delivers the interface and engine assets; your selected file is read locally on your device.
How does automatic format detection work?
The viewer checks a small sample of file bytes for known signatures and text patterns, together with the extension. Some text files match more than one format; in that case you choose the intended reader. Detection does not guarantee that a file is valid or supported.
Can I export a whole dataset or open a file from a URL?
No. Choose a file from your device; URL fetching is not provided. Table CSV export saves only the current page, at most 200 rows, with a 50 MiB generated-export cap. Download original keeps the selected file unchanged.
Is this local file viewer free to use?
Yes. The supported viewers are free, with no sign-in, subscription or billing. Choose a local file to start reading it in your browser.
Are my files uploaded or stored on a server?
No. File parsing, viewing and supported exports happen on your device. The website loads its code and engine assets, but does not upload your selected file. Closing or reloading clears the file session; downloaded files remain on your device.
Which file formats can I open?
CSV, TSV, JSON, JSONL (including NDJSON), Parquet, XML, YAML (including YML), EPUB, HEIC, PDF, DOCX, XLSX and PSD are supported. Capabilities and size limits differ by format; the supported-formats page lists the details.
Can I open any size file or use the viewer fully offline?
No. Each format has input and preview limits, and expanded data can exhaust browser memory earlier. A recent browser with WebAssembly and workers is needed. First-visit offline support is not provided; the site must load its code and assets.