Files
Previewing files
What opens in the browser without downloading: video, audio, PDF, PSD, code, spreadsheets, archives, 3D models and Nemi documents, plus what previews cannot do.
Select a file and press Space, or click it, and it opens in place. Arrow keys move to the next file in the folder, so a set of images can be flipped through without closing anything. The same viewer runs on a share page, so the person you sent a link to sees the file before they decide to download it, with no account and no plugin.
What opens#
| Kind | Opens | Worth knowing |
|---|---|---|
| Images | JPEG, PNG, GIF, WebP, AVIF, SVG, BMP, ICO | Zoom and pan, with a checkerboard behind transparent images. |
| Images we decode for you | PSD, PSB, HEIC, HEIF, TIFF, TGA, PCX, PPM and friends | No browser renders these, so Nemi decodes them and sends a flattened picture. Photoshop layers are not editable. |
| PDF, AI, EPS | Page by page, with search and zoom. | |
| Video | MP4, MOV, WebM, MKV, AVI, WMV, MPEG and more | Streamed, so it starts before the whole file has arrived. Whether an exotic codec plays is up to your browser. |
| Audio | MP3, WAV, FLAC, AAC, M4A, OGG, Opus, AIFF | With a waveform and a scrubber. |
| Code | Around 150 languages and config formats | Syntax highlighting. HTML also renders in a sandboxed frame, and code files can be edited and saved in place. |
| Text and markup | TXT, LOG, Markdown, reStructuredText, AsciiDoc, ICS, VCF | Markdown renders, with a toggle to the source. |
| Spreadsheets | CSV, TSV, XLSX, XLS, ODS, Numbers | A read-only grid, the first 2,000 rows and 100 columns. |
| Documents | DOCX, ODT, RTF, EPUB, PPTX, ODP | Flowed as text, presentations as a list of slides. |
| Archives | ZIP and the TAR family, including TAR.GZ | A read-only listing of what is inside, without unpacking it. |
| 3D | GLB, GLTF, OBJ, STL, FBX, DAE, PLY, 3MF | Orbit, zoom and reset. |
| Fonts | TTF, OTF, WOFF, WOFF2 | A live specimen you can type into. |
| Subtitles | SRT, VTT, ASS, SSA, SUB, LRC | As a timed list. |
| Nemi files | Docs, Sheets, Canvas and Forms | Opens the document itself. See Writing a document. |
What a preview does not do#
- RAW camera files are not rendered. CR2, CR3, NEF, ARW, DNG, RAF, ORF and the rest are recognised as photographs and can be converted, but decoding one is too heavy to do for a preview. Convert a copy to JPEG or PNG if you need to look at it in the browser.
- RAR, 7z, bzip2 and xz archives are not listed. Nemi lists ZIP and TAR archives. The others have to be opened on your own machine.
- Legacy .doc and .ppt are not rendered. The viewer says so and points at conversion rather than showing you nothing.
- Very long text is cut off. Text and code stop at 500,000 characters, with a note where they stop. Downloading gives you the whole file.
- Nothing is edited except code. Every other preview is read-only. Documents and spreadsheets you want to change belong in Docs and Sheets.
- Vault files are only opened by your own browser. We generate no previews or thumbnails for them, because we cannot read them. See What a vault is.
On a share page#
Recipients get the same viewer, in your colours, with a download button beside it. That is the point of it: somebody can check they were sent the right cut before starting an 18 GB download. If a share has a password or an expiry, the preview lives behind those the same as the download does. See Share links.
The preview says it could not load. Is my file damaged?
Usually not. Reload the page first: a preview that is generated on our side can time out on a very large image. If it fails twice, download the file and open it locally to check.
Why does my video have sound but no picture?
The container plays but your browser has no decoder for that video codec. Convert it to MP4 or WebM: see Converting files.
Can I stop people previewing and only let them download?
No, the preview is part of the share page. What you can control is who reaches the page at all, and for how long.
Related
Still stuck? Email support@nemilab.com and tell us what you were trying to do.