Security & Privacy
Exactly what happens to your audio and transcripts at every step. No marketing fluff — just how it actually works.
Three Levels of Privacy
Standard
Every user, every plan — including free
- HTTPS (TLS 1.3) for all data in transit
- Audio deleted immediately after processing
- Transcripts stored in our database
- We can read stored transcripts
- Data never sold or used for training
- Delete your data anytime
Private Transcript
Pro+ Available on Pro and Business plans
- Everything in Standard, plus:
- Transcript encrypted in your browser (AES-256-GCM) before saving
- We store only encrypted data — we cannot read it
- Key derived from your password, never sent to us
- ⚠ Audio is still processed on our servers during transcription
Private Cloud / Self-Hosted
Full isolation — from $99/mo
- Audio never leaves your infrastructure
- Transcription runs on your GPU
- No data sent to STT.ai servers
- Air-gapped support available
- True end-to-end privacy
What Actually Happens to Your Data
A transparent, step-by-step breakdown of how your audio and transcript are handled.
Standard (all users)
1
You upload audio or record live
Your file is sent over HTTPS (TLS 1.3) to our GPU server for transcription.
2
Audio is processed in memory
Our AI models transcribe your audio on the GPU. The audio is held in memory during processing — never written to disk — and deleted from memory immediately after.
3
Transcript is stored in our database
The text transcript, timestamps, and speaker labels are saved so you can access them later. We can read this data (this is how search, AI summaries, and sharing work).
4
You can delete everything anytime
Delete individual transcripts or your entire account from Privacy Settings. Deletion is permanent and immediate. Privacy Settings
With Private Transcript enabled
Steps 1-2 are the same — your audio must be processed on our servers to generate the transcript. The difference is what happens next:
3
Transcript is encrypted in your browser before saving
After transcription, the result is returned to your browser. Your browser encrypts it with AES-256-GCM using a key derived from your password (PBKDF2, 100K iterations). The encrypted blob is then sent to our servers for storage. We never see or store the encryption key.
4
We store only encrypted data
Our database contains only the encrypted blob. We cannot decrypt it. If our database were breached, your transcripts would be unreadable.
Important: Private transcript protects the stored transcript. During the transcription process itself, your audio is processed on our servers in order to generate the text. If your threat model requires that audio never touches third-party servers, consider Private Cloud or Self-Hosted. Private Cloud
What We Can and Can't See
We CANNOT see (with Private Transcript)
- Your stored transcript text
- Speaker names or labels (stored)
- Timestamps or word-level data (stored)
- Your encryption key or password
We CAN see (even with Private Transcript)
- Your audio during processing (deleted after)
- File name, size, duration (metadata)
- Language detected, model used
- Timestamp of transcription
- Your account info and billing
Technical Details
| Encryption algorithm | AES-256-GCM (authenticated encryption) |
| Key derivation | PBKDF2 with SHA-256, 100,000 iterations |
| IV (nonce) | Random 12 bytes per encryption (never reused) |
| Key storage | Never stored — derived from password on each session |
| Transport encryption | TLS 1.3 (HTTPS) + HSTS (1 year, preload) |
| Audio retention | Processed in memory, never written to disk, deleted immediately |
| Implementation | Web Crypto API (browser-native, no external libraries) |
| Source code | github.com/sttaigit/stt-encryption (MIT license) |
Private Transcript Trade-offs
Private transcript is opt-in because encrypting the stored transcript limits some features:
Works with encryption
- Viewing your transcripts
- Exporting (TXT, SRT, VTT, etc.)
- Downloading
- Editing (decrypted in browser)
Not available with encryption
- Server-side search across transcripts
- AI summaries and chat (server can't read data)
- Public sharing via link
- Team workspace collaboration
Need Audio to Never Leave Your Servers?
Private transcript protects the transcript at rest, but audio still passes through our GPU during processing. If your compliance or security requirements demand that audio never touches third-party infrastructure, these are your options:
Private Cloud
$499/mo
Dedicated GPU server managed by us. Your audio never leaves your isolated environment.
- Dedicated A100 GPU
- Isolated — no shared infrastructure
- Audio processed on your hardware only
- Full API access + SLA
Self-Hosted
$99/mo
Docker image. Your servers. Your GPU. Nothing leaves your network.
- Docker — runs on any NVIDIA GPU
- Air-gapped support — no internet required
- Model updates included
- Full control, full privacy
Our Commitments (All Users, All Plans)
- Audio files are deleted within 24 hours by default. Processed in GPU memory, source audio removed shortly after transcription. The only exception: if you opt in to "Contribute corrections + audio to Voice Lab" at Privacy Settings, audio is archived for up to 90 days while the corrections-ingest cron extracts clipped segments under CC-BY-SA-4.0. Privacy Settings
- Your data is never used for AI training unless you explicitly opt in at Privacy Settings (text-only corrections training and/or Voice Lab audio contributions — both default off). Privacy Settings
- We don't sell your data. Ever. To anyone.
- All traffic encrypted in transit via TLS 1.3 with HSTS.
- Delete your data anytime from Privacy Settings or by deleting your account. Privacy Settings
- Encryption code is open-source — audit it yourself (MIT license). audit it yourself
Open-Source Encryption
Our encryption library is fully open-source under the MIT license. Don't trust us — verify the code. No trust required, just math.
View on GitHub | View SourceReady to transcribe securely?
Upload your first file free. Private transcripts available on Pro and Business plans.
Start TranscribingFrequently Asked Questions
STT.ai security and encryption runs in your browser: paste a URL, upload a file, or record from your mic. STT.ai picks the AI model and returns the transcript in under 5 minutes. Export as TXT, SRT, VTT, DOCX, JSON, or PDF.
Yes — every visitor gets 600 free minutes/month on STT.ai, usable for STT.ai security and encryption the same as any other workflow. Paid plans starting at $5/month unlock longer files, private transcripts, and priority queueing.
STT.ai security and encryption runs on the same AI models as the rest of STT.ai — our best models reach 95-97% accuracy on clean speech (3-5% Word Error Rate on benchmarks). Switch models on the fly if the first pass is below your target.
STT.ai security and encryption can run on any of STT.ai's 10+ models — STT.ai Enhanced (most accurate), Whisper Large V3 (99 languages), NVIDIA Canary (#1 WER on supported langs), Whisper Turbo (fast), Moonshine (lightweight), and more.
Yes. Every transcript exports as SRT or VTT — works with YouTube, Vimeo, TikTok, VLC, and every major video player. The burn-subtitles tool overlays them onto video as hardsubs.
Yes. Speaker diarization automatically labels each voice (Speaker 1, Speaker 2, ...) and you can rename them in the built-in editor. Works across all models and languages.
Most STT.ai security and encryption jobs finish in under 5 minutes. A 1-hour audio file typically completes in 2-3 minutes with our fastest models. Speed depends on chosen model and current GPU load.
STT.ai security and encryption accepts 20+ formats — MP3, WAV, M4A, FLAC, OGG, MP4, MKV, MOV, WebM, AVI, and more. Output to TXT, SRT, VTT, DOCX, JSON, or PDF.
Yes. Audio files submitted to STT.ai security and encryption are processed and deleted by default. Pro plans add client-side encryption — even if STT.ai's database is breached, your transcripts are unreadable without your key. Data is never used for model training without explicit opt-in.
Yes. STT.ai offers a REST API with Python and Node.js SDKs, plus an MCP server for Claude and Cursor — all usable for STT.ai security and encryption workflows. Free API tier includes 100 minutes/month.
Yes. Every transcript opens in the built-in editor where you can correct words, rename speakers, adjust timestamps, and add notes. All changes save automatically.
Every transcript gets a unique shareable URL. Export to DOCX or PDF for email. Pro plans add password-protected and permanent links — useful for client work.
STT.ai handles 1,300+ platforms including YouTube, Vimeo, TikTok, SoundCloud, Zoom, Google Meet, podcast hosts, and more. URL transcription works with publicly-available content only — DRM-protected sources can't be transcribed.