Supported file types
Which files you can share as a link, how each one opens in the browser, and which types are blocked for safety.
You can share most everyday files as a link: documents, images, video, audio, data, code and archives. This page lists every type we accept, how each one opens for the person you send it to, and what we block.
Accepted file types#
If a file type is not in this table, the upload is refused with an “Unsupported file” message.
| Category | Extensions |
|---|---|
| Documents | .pdf, .txt, .md, .markdown, .docx, .xlsx, .pptx, .doc, .xls, .ppt |
| Images | .png, .jpg, .jpeg, .webp, .gif, .svg, .bmp, .avif, .ico |
| Video | .mp4, .webm, .mov |
| Audio | .mp3, .wav, .ogg, .m4a, .aac, .flac |
| Code | .html, .htm, .css, .js, .ts, .sql |
| Data | .log, .csv, .tsv, .json, .yaml, .yml, .xml |
| Archives | .zip |
iPhone photos
How each type opens#
Your viewer never needs an app or an account. The file opens in their browser like this:
| File type | What the viewer sees |
|---|---|
| Images (PNG, JPEG, WebP, GIF, SVG, BMP, AVIF, ICO) | Image viewer with zoom and full screen |
| Page viewer with page controls and zoom | |
| Video (MP4, WebM, MOV) | Video player in the page |
| Audio (MP3, WAV, OGG, M4A, AAC, FLAC) | Audio player in the page |
| Word (DOCX) | Shown as a document in the browser |
| Excel (XLSX, XLS) | Shown as a spreadsheet in the browser |
| PowerPoint (PPTX, PPT) and Word (DOC) | Download card, no in-browser preview yet |
| Markdown | Shown as a formatted page |
| Text, CSV, TSV, log, JSON, YAML, XML and code | Shown as readable text |
| HTML | Shown as a web page inside a sandbox |
| ZIP | Download card (archives can not be opened in the browser) |
When a download card is shown, the viewer can still save the file with Download file (or Download ZIP), unless you made the link view-only. Very large text or code files are also shown as a download card instead of being displayed in full.
HTML files run in a sandbox#
An HTML file is shown as a real web page, so its own scripts can run. It runs in an isolated sandbox that can not read your Link in Seconds account, cookies or other links. If an HTML page contains a login form, visitors see a safety warning first.
To publish a whole website with several pages, images and scripts, upload a ZIP as a hosted site instead. See Host a static website.
Blocked file types#
Programs, installers and scripts are never accepted, whatever the plan. Uploading one of these extensions is refused with “That file type isn't allowed for security reasons.”
.exe, .msi, .bat, .cmd, .com, .sh, .bash, .ps1, .scr, .jar, .app, .deb, .rpm, .dmg, .apk, .bin, .dll, .so, .php, .py, .rb, .pl
We check what is really inside the file#
A file name can lie. Renaming setup.exe to setup.pdf does not make it a PDF. So after your file reaches us, we read its first bytes, which identify the real format, and check that they match the type the name claims. A PDF must really be a PDF, an image must really be an image, and so on.
- Windows, macOS and Linux programs are refused even when renamed.
- Compressed archives hidden inside other types are refused. A ZIP is only accepted as a ZIP (or as an Office document, which is a ZIP inside).
- If a file does not match its type, for example a broken image, the upload stops and nothing is published.
On top of this check, every upload gets an automatic content safety scan. See Safety, scanning and reporting.
Related#
- Upload a file and get a link
- Plans and limits: file size limits per plan
Last updated 4 October 2026. Something unclear or missing? Tell us.