Bulk Transcribe Audio to SRT Subtitles Online Free
Generate SRT subtitles with accurate timestamps — 200x realtime with Whisper AI.
Drop up to 50 files at once — no install, no sign-up required.
Drop Audio or Video Files Here
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How it works
- 1 · Drop your files
Drag & drop audio or video files. Supports MP3, WAV, M4A, MP4, and more. No account required.
- 2 · We generate subtitles
Transcribed by OpenAI Whisper V3 Large with accurate timestamps. Encrypted in transit & at rest.
- 3 · Download & auto-delete
Get your SRT subtitle file in seconds. Files delete automatically after 1 hour.
Frequently Asked Questions
What is the SRT format?
SRT (SubRip Text) is the most widely supported subtitle format.
It contains numbered subtitle entries with timestamps and text.
SRT files work with virtually all video players, editors, and platforms including YouTube, Vimeo, and social media.
SRT vs VTT — which should I use?
Use SRT for:
- Video editing software
- Desktop players (VLC, QuickTime)
- Platforms like YouTube, Vimeo, or Facebook
Use VTT for HTML5 web video with <track> tags.
SRT has broader legacy compatibility across devices and software; VTT supports advanced styling and positioning for web.
Need web captions instead? Try Audio to VTT →
How accurate are the timestamps?
Our AI generates word-level timestamps using OpenAI Whisper V3 Large, one of the most accurate speech recognition models available.
Timestamps are typically accurate to within a few hundred milliseconds.
Can I customize the subtitle timing?
The generated SRT file uses Whisper's word-level timing, which works well for most use cases.
For fine-tuning, import the SRT into any subtitle editor (Aegisub, Subtitle Edit) to adjust timing, merge lines, or split captions.
The transcript text will be accurate — you're just adjusting presentation.
What are the limits for this converter?
| Tier | Max File Size | Max Files/Batch | Parallel Processing |
|---|---|---|---|
| Free | 100 MB | 50 files | 2 at once |
| Pro | 500 MB | 200 files | 4 at once |
| Business | 1024 MB | 1000 files | 6 at once |
Note: File size limits are specific to this converter. Batch and parallel processing limits apply to all images converters site-wide. See all converter limits →
How are credits calculated for this conversion?
Cost: 1 credit per minute
How it works:
- Files up to 1 minutes: 1 credit (minimum)
- 2 minutes: 2 credits
- 3 minutes: 3 credits
- 4 minutes: 4 credits
Example: A 10-minute file = 10 credits. A 180-minute (3h) audiobook = 180 credits.
Why per-minute? Audio conversion time scales with content duration, not file size. Longer audio requires proportionally more processing.
What are my daily and monthly credit limits?
Credit allocations vary by account tier:
| Tier | Daily Limit | Monthly Limit |
|---|---|---|
| Free | 50 credits/day | — |
| Pro | — | 10,000 credits/month |
| Business | — | 25,000 credits/month |
Daily credits (Free tier, including guests) reset every day at midnight UTC. Monthly credits (Pro & Business) reset on your billing cycle date.
Note: With 1 credit per minute, audio files under 1 MB cost 1 credit each. Pro users can convert 10,000 audio files per month.
Answers at a Glance
Quick answers to common questions.
- Are my files secure?
- How long do you keep my files?
- What metadata do you keep?
- What happens after I drop a file?
- Why are conversions so fast?
- How do you measure performance?
- What are the exact limits for each plan?
- Can I process files in bulk?
- Why did my file fail to convert?
- Do you use my files to train AI?
Choose Your Plan
Limits shown for Audio to SRT conversion. One subscription unlocks the entire Tools.FAST Network. Plans cover Convert.FAST, Compress.FAST, PDF.FAST (soon), and all future tools.
Free
For occasional personal use
- 100 MB per file
- 50 files per batch
- 2 parallel standard conversions
- 2 parallel AI conversions
- 50 credits/day
- Standard priority
- Email support
No sign-up required.
Create an account for your own credit pool.
Pro
For independent work
- 500 MB per file
- 200 files per batch
- 4 parallel standard conversions
- 4 parallel AI conversions
- 10,000 credits/month across Tools.FAST
- High priority
- Email & chat support
- One subscription for the entire Tools.FAST network
Business
For production scale
- 1 GB per file
- 1000 files per batch
- 6 parallel standard conversions
- 6 parallel AI conversions
- 25,000 credits/month across Tools.FAST
- Add seats to invite team members
- Highest priority
- Priority email & chat support
- One subscription for the entire Tools.FAST network
How Credits Work
- Usually 1 credit per conversion. Exact cost shown before you start.
- Credits refresh monthly on your billing cycle.
- Unused credits roll over, capped at your plan's monthly amount.
- One subscription, all sites. Works across Convert.FAST, Compress.FAST, and future tools.
Other Transcription Formats
Need a different output format for your transcription?