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SpectrShare

Frequently Asked Questions

Common questions about how it works

Basics

What is this platform and how does it work?

SpectrShare is a peer-to-peer (P2P) file sharing platform that runs entirely in your browser. Drop any files, click share, and send the link to your recipients. Files transfer directly between browsers - no cloud uploads, no accounts, no servers storing your data.

How it works:

  1. Drop any files into SpectrShare
  2. Click "Share" to get a unique link or QR code
  3. Recipients open the link and can download, view, or play files directly in their browser
  4. Everything transfers directly between browsers via encrypted WebRTC connections

Recipients can view images, play audio and video, read documents, spreadsheets, PDFs, emails, ebooks, and code files right in their browser - no downloads required for supported formats. All files are always available for download too.

Optional video conversion: If you're sharing video files and want recipients to be able to stream them with YouTube-like controls (play/pause/seek) and without downloading the whole file, you can enable video conversion. This processes the video in the background while your files are already available for download. Read more about how P2P video streaming works.

For a more detailed and technical explanation of how this works, check the Technical Details Page.

Any tips and tricks I should be aware of?

  • •Keep your browser tab open. Because everything runs from your browser, the tab has to stay open for recipients to download your files.
  • •Chrome and Edge provide the best experience as they can support a number of features that other browser don't. Firefox and Safari also work well, though larger file sizes require more memory. Check your browser's compatibility.
  • •SHA-256 hashes are computed for each file so recipients can verify the file wasn't corrupted during transfer.
  • •If you enable video conversion, your video files will be processed in the background for in-browser streaming.

Why did you build this?

I wanted a simple way to share files directly between devices without signing up for anything, without uploading to someone else's servers, and without worrying about storage limits or expiry dates. Modern browsers have powerful APIs (WebRTC, WebCodecs) that make it possible to transfer data directly between browsers - I just had to put it all together.

How can you make this free and without advertising?

All files transfer directly between your browser and your recipients' browsers. Because nothing is uploaded to the cloud and no data passes through our servers, it doesn't cost much to run.

Traditional file sharing platforms need expensive servers to store and serve your files. Since everything runs in your browser and data flows directly between peers, the server costs are minimal - just enough for the initial connection setup.

Do I need to create an account or sign up?

No account required. The platform works instantly without any sign-up, login, or email verification. Just drop your files and share.

Why no accounts? Our peer-to-peer architecture means your files never touch our servers (unless you enable a specific feature - see later), so there's nothing to tie to an account. This also maximizes your privacy - we don't track who you are or what you share.

What file types can be viewed in the browser?

All files can always be downloaded, regardless of type. Many file types can also be viewed directly in the browser without downloading the file to your disk:

Images

  • • JPG, PNG, GIF, WebP, SVG, AVIF, BMP
  • • Gallery view with thumbnails when sharing multiple images

Audio

  • • MP3, WAV, OGG, AAC, M4A, FLAC, WebM
  • • Inline player with play/pause and seek

Video

  • • MP4, WebM natively (browser-dependent)
  • • Any format via optional video conversion

Documents

  • • PDF viewer with page navigation
  • • Word documents (DOCX, DOC, ODT) with formatting
  • • RTF with rich text rendering
  • • Markdown rendered with styling
  • • Syntax-highlighted code/text (JSON, YAML, Python, JS/TS, and more)

Spreadsheets

  • • XLSX, XLS, ODS
  • • Table view with multi-sheet navigation

Emails

  • • EML files with header display (from, to, subject, date)
  • • HTML body rendering and attachment list

Ebooks

  • • EPUB reader with chapter navigation
  • • Table of contents and keyboard shortcuts

Files that can't be previewed in the browser (archives, executables, proprietary formats, etc.) are always available for download. Every file gets a download button regardless of type.

Are there any file size limits?

There is no per-file size limit for sharing. The file transfer pipeline is fully streaming and tries to never load an entire file into memory.

Download method by browser:

  • • Chrome and Edge: Files stream directly to disk via the File System Access API - unlimited size
  • • Firefox and Safari: A Service Worker handles streaming downloads - works well for most file sizes
  • • Fallback: Large files (roughly >500MB) may be limited by available memory on some browsers

Video conversion limits

If you enable video conversion for in-browser streaming, the video processing happens in browser memory in a streaming fashion. The highest memory part is if an audio conversion needs to be handled by ffmpeg (not hardware supported) as ffmpeg requires the whole video file to be loaded into memory. This limit only applies to the host during conversion - viewer memory usage is low.

Privacy & Security

How private is my content? Is it stored anywhere?

Your files never touch our servers, unless you enable a specific feature labelled "Improve reliability at the expense of privacy." This switches on TURN support which enables more users to connect to you, however in specific circumstances it requires data to transit our servers. The traffic is fully encrypted in these cases, and we don't store any of your data.

Note: I do have Google Analytics enabled on this site, which provides aggregated usage statistics (ie. "10 people from USA accessed the page")

Privacy Measures

  • • No server storage: Your files are never saved on our servers
  • • Direct P2P: Data goes directly from your browser to your recipients
  • • Browser-only processing: All processing happens locally on your device
  • • No uploads: Nothing is uploaded to external servers

The only server involvement is for the initial connection setup (signaling). This just exchanges connection information - your files never pass through. Once the P2P connection is established, everything flows directly between browsers.

What happens to your files:

  1. Files are read directly from your disk and transmitted via encrypted WebRTC
  2. Data flows directly to connected recipients - no server in the path
  3. When you close the browser, everything is immediately gone - nothing persists on any server

While your files are not stored on any server, you should assume that your recipients can save what they receive - through downloads, screen capture, or other means.

Additionally there is a password feature you can add to your share session. The share URL is sufficiently random that it would take a typical brute force attack around 270,000 years to reach a specific session, however adding a password means that even site admins can't connect to access your files without also knowing the password (and the passwrod is never sent over the internet.) Learn more about why SpectrShare doesn't use cloud storage.

What security features are built-in?

Connection Security:

  • • DTLS encryption for all data
  • • ICE candidate validation
  • • Automatic NAT traversal
  • • Ephemeral TURN credentials

Access Control:

  • • Unique share IDs
  • • Session-based connections
  • • Optional password protection
  • • No persistent storage

File Safety:

  • • SHA-256 hash verification - recipients can verify file integrity
  • • Executable file warnings - alerts before downloading potentially dangerous files (.exe, .bat, .sh, etc.)
  • • Filename sanitization - prevents path traversal and other filename-based attacks

All connections use industry-standard WebRTC security protocols with end-to-end encryption between browsers.

How many people can connect simultaneously?

The number of simultaneous recipients depends on your device's capabilities and network connection:

Typical Limits:

  • • Desktop/laptop (good connection): 5-10 recipients
  • • Mobile device: 1-3 recipients
  • • Limited bandwidth: 1-2 recipients

Factors:

  • • Upload bandwidth available
  • • CPU processing power
  • • Available memory
  • • Number and size of files being shared

Technical Requirements

Which browsers are supported?

File sharing works in all modern browsers with WebRTC support, including mobile browsers. Chrome and Edge provide the best overall experience with streaming downloads to disk.

Required for file sharing:

  • • WebRTC DataChannels: P2P data transmission (supported in all modern browsers)
  • • File System Access API (Chrome/Edge): Streaming downloads directly to disk
  • • Service Worker (Firefox/Safari): Alternative streaming download method

Additionally needed for video conversion:

  • • WebCodecs API: Hardware-accelerated video processing
  • • MediaSource Extensions: Adaptive video playback
  • • WebAssembly: Software fallback processing

What are the network requirements?

Minimum Requirements:

  • • Host upload: 5+ Mbps
  • • Recipient download: 3+ Mbps
  • • Latency: <200ms preferred
  • • Connection: Stable broadband

NAT Type Compatibility:

  • • Open NAT: Excellent
  • • Moderate NAT: Good
  • • Strict NAT: Limited
  • • Symmetric NAT: May fail

Network Test

Use the connection testing tool to check your NAT type and connection capabilities before sharing.

Why is video conversion sometimes slow?

This only applies when you enable the optional "Convert video files for in-browser viewing" feature. Behind the scenes, there are two different pathways for processing your video:

Fast Path: Hardware Accelerated

The primary path uses Mediabunny which taps into your browser's WebCodecs and WebGL support. This is very fast and hardware accelerated, but has limited format support depending on your browser.

Slow Path: Software Fallback

If your video format isn't supported by the fast path, we fall back to ffmpeg.wasm. This has very wide codec support, but is entirely CPU-based and single-threaded, which results in much slower conversion times.

If your video is in MP4 format with H.264 codec, it will almost always use the fast hardware-accelerated path. Remember that video conversion is entirely optional - your video files are always available for download immediately regardless.

Troubleshooting

Connection fails or people can't join

Common Causes & Solutions:

1. Firewall or NAT Issues

  • • Run the network test on the home page
  • • Try using a mobile hotspot as a test
  • • Enable the "Improve reliability at the expense of privacy" feature

2. Browser Compatibility

  • • Use Chrome, Edge, or Opera for best results
  • • Update to the latest browser version
  • • Try an incognito/private window

3. Network Performance

  • • Check your upload speed (needs 5+ Mbps)
  • • Close other bandwidth-heavy applications
  • • Use ethernet instead of Wi-Fi if possible

File downloads fail or are slow

Download Failures

  • • Ensure the host's browser tab is still open - if they close it, files become unavailable
  • • Check your connection - the same P2P requirements apply
  • • Try the download again - the retry mechanism handles temporary network issues
  • • If hash verification fails, the file may have been corrupted in transit - retry the download

Large File Issues

  • • Use Chrome or Edge for large files - they can stream directly to disk
  • • On mobile, very large files may exceed available memory
  • • Close other tabs and applications to free up memory
  • • On Firefox/Safari, a Service Worker handles the download - ensure it's enabled

Video conversion is slow or causes issues

This only applies if you've enabled the optional "Convert video files for in-browser viewing" feature. Your files are always available for download immediately regardless of conversion status.

Slow Conversion

  • • MP4 with H.264 codec uses the fast hardware-accelerated path - other formats may use slower software conversion
  • • You can pre-convert your video using Private Video Converter or Handbrake

Memory Issues

  • • Close other browser tabs and applications
  • • Use lower quality settings to reduce memory usage
  • • Try a smaller video file or lower resolution
  • • Chrome has the best memory handling for video conversion

Video playback issues for recipients

This applies to the in-browser video player for converted videos.

Playback Problems

  • • Refresh the page and rejoin the share session
  • • Try a different browser (Chrome recommended)
  • • Ensure stable internet connection
  • • The video can always be downloaded and played locally

Buffering Issues

  • • Check your download speed (needs 3+ Mbps)
  • • Switch to a lower quality if available
  • • Pause for a few seconds to build buffer
  • • Close other bandwidth-using applications

Give it a try. If you have more questions, get in touch.

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