How do I generate subtitles automatically?

Sign up for free, upload your video or audio file, and FlowSub automatically generates accurate subtitles using OpenAI Whisper AI. The process usually takes 1–3 minutes. Download in SRT, VTT, ASS, or TXT format.

Is FlowSub free to use?

Starter ($8.99/mo) covers full transcription + FFmpeg tools. Pro ($16.99/mo) unlocks all AI generation: voice, music, image, video. Elite ($29.99/mo) includes everything with double the credits.

What video and audio formats are supported?

FlowSub supports MP4, MKV, MOV, AVI, WebM (video) and MP3, WAV, M4A, OGG (audio). Maximum file size is 500 MB.

How accurate is AI subtitle generation?

FlowSub uses OpenAI Whisper, achieving near human-level accuracy on clear audio. Accuracy depends on audio quality, speaker clarity, and background noise.

Can I get subtitles in multiple languages?

Yes. Whisper supports 29+ languages and auto-detects the spoken language. Pro users can also translate subtitles into any language on demand.

What subtitle formats does FlowSub export?

SRT (most compatible), VTT (web standard), ASS (advanced styling, Pro), and TXT (plain transcript). All formats generated with every transcription.

Free — No Sign-Up Required

AI Tone Rewriter

Rewrite any text with a different tone — formal, casual, persuasive, humorous, professional, empathetic. Perfect for scripts, emails, and content. Free, no sign-up.

No credit cardFirst file freeNo watermark500 MB free

Drop your file here

or click to browse

Subtitle: SRT, VTT, ASS, TXT, CSV · Video: MP4, MKV, WebM, MOV · Audio: MP3, WAV, AAC, FLAC · Free, no sign-up

⚡ Under 3 minutes🔒 No watermark, ever💰 8× cheaper than Veed✅ No sign-up for first file

How to use this tool

Three easy steps. No sign-up needed for your first file.

Paste your text

Any text — script, email, article, social post. Up to 10,000 characters.

Choose target tone

Formal, casual, persuasive, humorous, professional, empathetic, urgent, inspirational.

Get rewritten text

AI rewrites preserving meaning while transforming tone. Copy, download, or edit further.

Frequently asked questions

Does AI preserve the original meaning?

Yes. The AI is prompted to maintain factual accuracy and core message while adjusting only the tone, vocabulary, and sentence structure to match the target tone.

What tones are available?

Formal (business, academic), Casual (friendly, conversational), Persuasive (sales, marketing), Humorous (witty, light), Professional (polished, competent), Empathetic (warm, understanding), Urgent (immediate, pressing), Inspirational (motivating, uplifting).

Can I use this for YouTube scripts?

Yes. Paste your draft script and transform it through different tones to find the right voice for your channel. Many creators use it to adapt scripts across different video styles.

Is my text saved or used for training?

No. Text is processed and discarded. FlowSub does not store, log, or use your text for model training. Full privacy.

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Ready to use AI Tone Rewriter?

First file free — no sign-up. Create a free account to unlock all features, larger files, and 5 free credits.

Rewrite Tone Free ← Back to all free tools

Free — No Sign-Up Required

AI Tone Rewriter

Rewrite any text with a different tone — formal, casual, persuasive, humorous, professional, empathetic. Perfect for scripts, emails, and content. Free, no sign-up.

No credit cardFirst file freeNo watermark500 MB free

Drop your file here

or click to browse

Subtitle: SRT, VTT, ASS, TXT, CSV · Video: MP4, MKV, WebM, MOV · Audio: MP3, WAV, AAC, FLAC · Free, no sign-up

⚡ Under 3 minutes🔒 No watermark, ever💰 8× cheaper than Veed✅ No sign-up for first file

How to use this tool

Three easy steps. No sign-up needed for your first file.

Paste your text

Any text — script, email, article, social post. Up to 10,000 characters.

Choose target tone

Formal, casual, persuasive, humorous, professional, empathetic, urgent, inspirational.

Get rewritten text

AI rewrites preserving meaning while transforming tone. Copy, download, or edit further.

Frequently asked questions

Does AI preserve the original meaning?

Yes. The AI is prompted to maintain factual accuracy and core message while adjusting only the tone, vocabulary, and sentence structure to match the target tone.

What tones are available?

Can I use this for YouTube scripts?

Yes. Paste your draft script and transform it through different tones to find the right voice for your channel. Many creators use it to adapt scripts across different video styles.

Is my text saved or used for training?

No. Text is processed and discarded. FlowSub does not store, log, or use your text for model training. Full privacy.

Related free tools

Accent Generator

Apply or change accents with AI. Convert your voice to British, American, Australian, Indian, and 20+ more accents. TTS mode or voice conversion. Free, no watermark.

Try free →

Add Audio to Video

Add background music, voiceovers, or sound effects to any video. Replace the original audio track or mix both. MP4 output. 500 MB. Free, no watermark.

Try free →

AI ASMR Voice Generator

Generate ASMR-style whispers and soft-spoken AI voices. Perfect for relaxation content, sleep aids, and meditation. Free, no watermark. 500 MB limit.

Try free →

AI Audiobook

Turn any book, script, or document into a narrated audiobook with AI voices. 50+ voices, chapter markers, natural pacing. 500 MB. Free, no watermark.

Try free →

AI Dubbing

Replace video audio with AI-generated voiceovers in 29+ languages. Preserve emotion, timing, and tone. Free, no watermark. Upload up to 500 MB.

Try free →

AI Sound Effect Generator

Generate sound effects from text descriptions. Type 'rain on a tin roof' or 'sci-fi door opening' — AI creates the sound. 500+ categories. Free, royalty-free.

Try free →

Ready to use AI Tone Rewriter?

First file free — no sign-up. Create a free account to unlock all features, larger files, and 5 free credits.

Rewrite Tone Free ← Back to all free tools