Captio AI vs Soniox
Captio AI and the Soniox app side by side: live captions, who is talking, translation, captions with the screen off, files, free plan and price, all sourced.
Facts checked on each company's own pages. How we compare
The short answer
Use Soniox if you want the same app on your phone, a Mac or Windows computer and the web, or want to ask your own questions about a transcript. Use Captio AI if you want captions that keep going with the iPhone screen locked, people shown by name with Recognize Voices on iPhone, free credits every day, a lower price for unlimited use, or audio and video files transcribed on your phone without an account.
Choose Soniox if
you want one app on your phone, your Mac or Windows computer and the web, or want to ask your own questions about a transcript and get quotes from each speaker.
Choose Captio AI if
you want captions that keep going with the iPhone screen locked, names of the people you talk to from their voice (iPhone), free credits every day, a lower price for unlimited use, or to transcribe audio and video files on your phone.
Captio AI vs Soniox, feature by feature
Tap any fact to see the details and the page it comes from.
| Feature |  Captio AICaptio AI |  SonioxSoniox |
|---|---|---|
| Works onThe phone you already have decides what you can use. |  Captio AIYes: iPhone, iPad, AndroidOn the App Store (also listed for Apple silicon Macs and Apple Vision) and on Google Play since October 2026. Sources: Apple App Store listing, Google Play listing |  SonioxYes: iPhone, iPad, Android, Mac, Windows, webPhone apps on the App Store and Google Play, a desktop app for Mac and Windows, and a web app to review and share recordings. The web app cannot record. Sources: Apple App Store listing, Google Play listing, Soniox App (soniox.com), Soniox Help Center |
| NeedsOlder phones are often left out of built-in features. | Captio AIYes: iOS 15.1 or laterThe App Store lists iOS 15.1 or later for iPhone. Source: Apple App Store listing | SonioxYes: iOS 16.4 or laterThe App Store lists iOS 16.4 or later for iPhone and iPadOS 16.4 or later for iPad (October 2026). The Android version needed is not shown on the Google Play page we opened. Source: Apple App Store listing |
| Captions people in the roomSpeech picked up by the phone's microphone, for face-to-face conversations. | Captio AIYes, from the phone's microphoneSpeech in the room appears as text while the person is still talking. Sources: Apple App Store listing, Live Captions (Captio AI) | SonioxYes, from the phone's microphoneSoniox says the app works through the phone's microphone and captions speech around you word by word. Live captions need internet and the app open on screen. Sources: Soniox: Hearing accessibility, Soniox Help Center: How to transcribe, Soniox Help Center: Mobile App FAQ |
| Group conversationsAt a table or in a meeting, voices come from every side. | Captio AIPartly: One phone: speaker labels, names, directionOne phone captions the whole table and labels each speaker. On iPhone it can name people by their voice, and on iPhone 16 and later a wave shows which side a voice comes from. Shared folders let several people add recordings to one place; live captions are not joined across phones. Sources: Apple App Store listing, Recognize voices (Captio AI) (Captio AI), Speaker direction (Captio AI) (Captio AI), Live Captions (Captio AI) | SonioxPartly: One phone, speaker labelsOne phone captions the group and labels each speaker. Shared projects organise saved transcripts; Soniox describes no way to join several phones into one live conversation. |
| Shows who is talkingWithout it, a group conversation is one block of text. | Captio AIYes, live and saved; names by voice on iPhoneSeparates speakers (Speaker 1, Speaker 2). On iPhone it can learn saved voices and show their names instead. Sources: Apple App Store listing, Recognize voices (Captio AI) (Captio AI), Live Captions (Captio AI) | SonioxYes, Speaker 1, 2; rename after savingSpeaker diarization labels the text Speaker 1, Speaker 2 and so on, live and in saved recordings. You can rename speakers in a saved recording, and every line of that speaker updates. Sources: Apple App Store listing, Soniox Help Center: Improving accuracy, Soniox Help Center: Managing & sharing, Soniox: Hearing accessibility |
| Remembers people's voicesCaptions that say "Mum" instead of "Speaker 2", every time she talks. | Captio AIYes, Recognize Voices (iPhone)Save someone's voice once (about 20 seconds of talking, or an audio file) and their name and emoji show on every line they say, live and in saved recordings, instead of "Speaker 2". Voiceprints are made on the iPhone and never uploaded. When someone new talks for a while, Captio AI asks who it is. Free plan: your own voice plus one other person; Plus: more people. Source: Recognize voices (Captio AI) (Captio AI) | SonioxNot statedSoniox labels speakers Speaker 1, Speaker 2 and lets you rename them; it doesn't say it remembers a voice in later recordings. |
| Shows where a voice comes fromAt a busy table, knowing where to look helps you follow who is talking. | Captio AIYes, on iPhone 16 and laterWith the iPhone flat on the table, a wave grows at the edge of the captions on the side the voice comes from, in that speaker's colour, while new words appear. It uses the iPhone's spatial microphones (not AirPods or an external mic), works in Live Captions and Live Translator, is calculated on the phone, and is free. Source: Speaker direction (Captio AI) (Captio AI) | Soniox Not stated |
| Alerts for soundsDoorbells, alarms and a baby crying, as a notification. | Captio AIYes, sounds in the captions; alerts vibrateRecognize Sounds (iPhone and iPad) writes sounds into the captions where they happen, like [doorbell rings], in Live Captions, Live Translator and uploaded files. A doorbell, knocking, a smoke alarm, a siren, a phone ringing or a baby crying makes the phone vibrate, with a notification when the screen is locked during a recording. It works while Captio AI is recording, not as an always-on alarm. Recognized on the phone; free; not on Android yet. Source: Recognize sounds (Captio AI) (Captio AI) | SonioxNot statedSoniox's app pages and help centre describe no alerts for sounds such as a doorbell or an alarm. Sources: Soniox App (soniox.com), Soniox: Hearing accessibility |
| Languages for live captionsThe number of spoken languages it can caption live. | Captio AIYes: 60+ languagesCaptions and translation in 60+ languages, including speech that switches languages mid-sentence. Sources: Apple App Store listing, Live Captions (Captio AI) | SonioxYes: 60+ languagesSoniox lists 60 languages for live captions and translation, including speech where people switch languages mid-sentence. You can set language hints for the languages you expect. Sources: Soniox App (soniox.com), Soniox: Hearing accessibility, Soniox Help Center: Improving accuracy |
| Live captions without internetPlanes, basements, hospitals and trips abroad often have no signal. | Captio AIPartly: Records offline, captions laterLive captions need internet. Without a connection it keeps recording and transcribes automatically when the phone is back online. Sources: Apple App Store listing, Live Captions (Captio AI) | SonioxPartly: Records offline, transcribes laterLive transcription works only when the app is online and open on screen. Offline or in the background it keeps recording, and the transcript is made once you are back online. Sources: Soniox Help Center: How to transcribe, Soniox Help Center: Mobile App FAQ, Soniox App (soniox.com) |
| Live translationFor a conversation in a language you don't read. | Captio AIYes, live, two-way modeLive translation next to the original captions, with a two-way mode where each person reads the other in their own language. Sources: Apple App Store listing, Live Translator (Captio AI) | SonioxYes, live, one-way or two-wayTranslate to shows the original and a translation into one language. Translate between shows two boxes, one per language, and the top box can be rotated for the person sitting across from you. Sources: Soniox Help Center: How to translate, Apple App Store listing |
| Saves transcriptsTo read a lecture, appointment or meeting again later. | Captio AIYes, with audio, syncedRecordings are saved with their audio in a searchable library and synced to your account. | SonioxYes; audio on the phone, text syncedSaved audio stays only on your phone and is deleted if you uninstall the app. Transcripts, translations and summaries sync to your account and the web app. Playback needs the audio on the phone. Sources: Soniox Help Center: Privacy & data, Soniox Help Center: Mobile App FAQ, Soniox Help Center: Managing & sharing |
| Export and shareTo send notes to yourself, a carer or a colleague. | Captio AIYes: Text, link, PDF, emailShare a transcript or summary as text, a link, a PDF, an email, or a prompt for an AI chat. Source: AI Summary (Captio AI) | SonioxYes: Link, text, audio file (.m4a)Share a private web link to the transcript with speaker labels and AI results, share the text, or send the audio file (.m4a) through the phone's share menu. |
| Transcribes audio and video filesFor recordings and videos that have no captions. | Captio AIYes: Audio and video filesUpload audio or video and get a full transcript with speaker labels. Sources: Apple App Store listing, Audio Transcription (Captio AI) | SonioxPartly: Audio files in the Mac and Windows appThe help centre describes uploading an existing audio file in the desktop app for Mac and Windows. It describes no file import in the phone app. Sources: Soniox Help Center: Smart Scribe on desktop, Soniox Help Center: Getting started |
| AI summariesKey points and to-dos from a long transcript. | Captio AIYes: Summary, key points, to-dosTurns transcripts into summaries, key points, notes, to-dos and follow-up messages. Free plan: 3 summaries in total. Sources: Apple App Store listing, AI Summary (Captio AI) | SonioxYes: Summary, to-dos, quotes, your own promptsSummary, key points, to-do list, speaker summary, speaker quotes and named entities, plus your own questions about a transcript (custom prompts). On the Free plan, AI actions use credits. Sources: Soniox Help Center: AI actions, Apple App Store listing |
| Text size and coloursCaptions have to be readable at arm's length, flat on a table. | Captio AIYes: Text size, colours, contrastText size, background colour and contrast can be adjusted. Source: Live Captions (Captio AI) | SonioxYes: Larger text, dark mode, rotate textThe App Store lists larger text (200% or more) and a dark interface. In two-way translation the top box can be turned to face the other person. Soniox lists no caption colour settings. Sources: Apple App Store listing, Soniox Help Center: How to translate |
| Where speech is processedOn the phone or in the cloud, and whether audio is kept. | Captio AIYes: Cloud; audio not stored on its serversSpeech is processed by third-party speech recognition after you agree. Audio is not stored on Captio AI's servers; content is never sold or used to train AI models. Source: Captio AI privacy policy | SonioxYes: Cloud for live text; audio kept on the phoneWhile online, audio streams for live transcription and is processed immediately, not stored. Saved audio stays on the phone; audio uploaded for processing is deleted afterwards. Soniox says it never uses your audio to train AI. Sources: Soniox Help Center: Privacy & data, Soniox Help Center: Mobile App FAQ, Soniox privacy policy, Apple App Store listing |
| Account neededSome people want to open the app and start, with no sign-up. | Captio AIPartly: OptionalSign in with Apple or Google to sync, or skip and use it on one phone. Source: Captio AI privacy policy | SonioxYes, a Soniox accountYou create an account in the app or on the web; the same account works in the phone and web apps. Soniox's developer Console is a separate product with separate accounts. |
| Free planWhat you can do without paying. | Captio AIYes: 100 free credits a day + 3 summariesFree every day: 100 free credits a day for live captions or transcription, and 3 AI summaries in total. Sources: Apple App Store listing, Captio AI for AI assistants (llms.txt) | SonioxYes: 10 credits a weekFree credits are added every week and don't roll over; Soniox doesn't say how much audio a credit covers. When they run out, live transcription turns off but the app keeps recording. Soniox says Free and Pro use the same models. Sources: Soniox Help Center: Getting started, Soniox Help Center: Plans, Soniox pricing page |
| Paid plansPrices as listed by the company, with the country and date. | Captio AIYes: US$14.99/month or US$79.99/yearCaptio AI Plus on the US App Store, October 2026. No free trial. Prices differ by country. Source: Apple App Store listing | SonioxYes: Pro US$19.99/month or US$119.99/yearSoniox Pro on the US App Store, October 2026 (US$19.99 to US$119.99 on Google Play). The help centre lists US$19.99 a month, or US$120 a year at 50% off. Pro is unlimited and can't be shared with family. Sources: Apple App Store listing, Google Play listing, Soniox Help Center: Plans, Soniox pricing page |
What actually sets them apart
How much does Soniox cost?
Soniox is free with 10 credits a week that don't roll over; Soniox doesn't say how much audio a credit covers. Soniox Pro costs US$19.99 a month or US$119.99 a year on the US App Store (October 2026). Captio AI is free with 100 free credits a day and 3 AI summaries in total. Captio AI Plus costs US$14.99 a month or US$79.99 a year on the US App Store (October 2026), with no free trial.
Sources: Soniox Help Center: Getting started, Soniox Help Center: Plans, Soniox pricing page, Apple App Store listing, Google Play listing, Apple App Store listing, Captio AI for AI assistants (llms.txt)
Does Soniox keep captioning with the screen off?
No. Soniox's help centre says live transcription works only when the app is online and open on screen. In the background it keeps recording, and the transcript is made after you save. Captio AI keeps captioning with the iPhone screen locked.
Sources: Soniox Help Center: How to transcribe, Soniox Help Center: Mobile App FAQ, Soniox App (soniox.com), Captio AI widgets and Live Activity
Does Soniox work on a computer?
Yes. Soniox has a desktop app for Mac and Windows, and a web app to read, organise and share recordings; the web app can't record. Captio AI runs on iPhone, iPad and Android.
Sources: Apple App Store listing, Google Play listing, Soniox App (soniox.com), Soniox Help Center, Apple App Store listing, Google Play listing
Where does Soniox keep my recordings?
On your phone. Saved audio stays only on the phone and is deleted if you uninstall the app; transcripts, translations and summaries sync to your Soniox account. Soniox says it never uses your audio to train AI. Captio AI saves recordings with their audio in a library synced to your account; audio is not stored on Captio AI's servers, and your content is never used to train AI models.
Sources: Soniox Help Center: Privacy & data, Soniox Help Center: Mobile App FAQ, Soniox Help Center: Managing & sharing, Soniox privacy policy, Apple App Store listing, Apple App Store listing, Captio AI privacy policy
Can Soniox tell you who is talking by name?
In a saved recording, after you rename the speakers. Soniox labels the text Speaker 1, Speaker 2, live and in saved recordings, and renaming a speaker updates every line of theirs in that recording; Soniox's pages don't say it remembers a voice in later recordings. Captio AI's Recognize Voices on iPhone shows the names of people whose voices you saved, like "Mum" instead of "Speaker 2", live and in saved recordings. On iPhone 16 and later, Speaker Direction shows which side a voice comes from.
Sources: Apple App Store listing, Soniox Help Center: Improving accuracy, Soniox Help Center: Managing & sharing, Soniox: Hearing accessibility, Recognize voices (Captio AI) (Captio AI), Speaker direction (Captio AI) (Captio AI)
Can Soniox transcribe an audio or video file on my phone?
Only on a computer, as Soniox describes it: its help centre explains uploading audio files in the Mac and Windows app, and no file import in the phone app. Captio AI transcribes audio and video files in the phone app, with speaker labels.
Sources: Soniox Help Center: Smart Scribe on desktop, Soniox Help Center: Getting started, Apple App Store listing, Audio Transcription (Captio AI)
Where each one wins
Where Soniox is the better choice
One account works on your phone, a Mac or Windows computer and the web, with one shared balance of credits. Captio AI runs on iPhone, iPad and Android.
Sources: Apple App Store listing, Google Play listing, Soniox App (soniox.com), Soniox Help Center, Soniox Help Center: Desktop App, Apple App Store listing, Google Play listing
You can ask your own questions about a transcript, and get a summary per speaker, quotes from each speaker and a list of the names mentioned.
Sources: Soniox Help Center: AI actions, Apple App Store listing
In two-way translation, the top box turns to face the person sitting across from you.
It also types with your voice in any app: as a keyboard on iPhone, and in the Mac and Windows app.
Sources: Soniox App (soniox.com), Soniox Help Center: Mobile App FAQ, Soniox Help Center: Desktop App
Where Captio AI is the better choice
It keeps captioning with the iPhone screen locked, transcribes audio and video files in the phone app, and works without an account. Soniox's live transcription works only with the app open on screen, Soniox describes file upload only in its desktop app, and it needs an account.
Sources: Captio AI widgets and Live Activity, Apple App Store listing, Audio Transcription (Captio AI), Captio AI privacy policy, Soniox Help Center: How to transcribe, Soniox Help Center: Mobile App FAQ, Soniox App (soniox.com), Soniox Help Center: Smart Scribe on desktop, Soniox Help Center: Getting started
Its free plan gives 100 free credits every day, and Captio AI Plus costs US$14.99 a month or US$79.99 a year. Soniox's free credits come once a week, and Soniox Pro costs US$19.99 a month or US$119.99 a year (US App Store, October 2026).
Sources: Apple App Store listing, Captio AI for AI assistants (llms.txt), Soniox Help Center: Getting started, Soniox Help Center: Plans, Soniox pricing page, Apple App Store listing, Google Play listing
Recognize Voices (iPhone): save someone's voice once and their name, like "Mum" instead of "Speaker 2", shows on every line they say, live and in saved recordings. Voiceprints stay on the iPhone. Soniox lets you rename speakers in a saved recording; its pages don't say it remembers a voice.
Sources: Recognize voices (Captio AI) (Captio AI), Soniox Help Center: Managing & sharing
Speaker Direction (iPhone 16 and later): with the phone flat on the table, a wave at the edge of the captions shows which side a voice comes from.
Source: Speaker direction (Captio AI) (Captio AI)
Recognize Sounds (iPhone and iPad): sounds like "[doorbell rings]" are written into the captions where they happen and stay in the saved recording, and a doorbell, a smoke alarm or a baby crying makes the phone vibrate. Soniox's pages don't describe alerts for sounds.
Sources: Recognize sounds (Captio AI) (Captio AI), Soniox App (soniox.com), Soniox: Hearing accessibility
Try Captio AI free
It depends on where you are
Meetings on a Mac or Windows computer
Soniox's desktop app records, transcribes and translates on Mac and Windows. Captio AI runs on iPhone, iPad and Android.
Captions for this situationA recorded lecture or a video file on your phone
Captio AI transcribes audio and video files in the phone app. Soniox describes file upload only in its desktop app.
Captions for this situationA family dinner with several people
Both label each speaker from one phone in the middle of the table. On iPhone, Captio AI shows the names of voices you saved while people talk, and on iPhone 16 and later shows which side a voice comes from; in Soniox you rename speakers after saving.
Captions for this situationA conversation in two languages across a table
Both translate live in 60+ languages, with a two-way mode. Soniox can turn the top box to face the other person.
Captions for this situationCaptions every day on a budget
Captio AI gives 100 free credits every day, and Captio AI Plus costs US$14.99 a month. Soniox gives 10 credits a week, and Pro costs US$19.99 a month (US App Store, October 2026).
No signal on a plane or in a basement
Neither shows live captions without internet. Both keep recording and write the transcript when you're back online.
Facts you can check, not opinions.
From their own pages
Every fact comes from the company's website, help pages, privacy policy or store listing. Tap any fact to see the page it comes from.
Checked 28 October 2026
Each source has the date we opened it. If a company doesn't say something publicly, the table says "Not stated" instead of guessing.
We make Captio AI
So it's described with the same rules as every other app, limits included, and each page says where the other app is the better choice.
Something out of date? hello@captioai.app
Frequently asked questions
Is the Soniox app free?
Yes, to start. The Free plan gives 10 credits a week, shared by the phone, web and desktop apps. They don't roll over, and Soniox doesn't say how much audio a credit covers. When they run out, live transcription stops but the app keeps recording. Captio AI's free plan gives 100 free credits a day and 3 AI summaries in total.
How much does Soniox Pro cost in the US?
US$19.99 a month or US$119.99 a year on the US App Store (October 2026); Soniox's help centre lists the yearly plan at 50% off. Pro is unlimited and can't be shared with family. Captio AI Plus costs US$14.99 a month or US$79.99 a year on the US App Store (October 2026), with no free trial.
Can Soniox caption a doctor's appointment?
Yes. Soniox's accessibility page describes captioning medical appointments, and the app saves the transcript and can make a summary and a to-do list. Live captions need internet and the app open on screen. Captio AI captions the appointment live, keeps the recording with its audio, and turns it into a summary and to-dos.
Does Soniox work offline on a plane?
It records, but it doesn't caption live. Without internet, Soniox keeps recording and writes the transcript when you're back online. Captio AI works the same way: live captions need internet, and offline it keeps recording and transcribes when the phone reconnects.
Can Soniox translate Spanish into English live?
Yes. Spanish and English are among Soniox's 60+ languages. Translate to shows the original and the English translation; Translate between shows one box per language for a two-way conversation. Captio AI also translates live in 60+ languages, with the translation next to the original captions and a two-way mode.
Does Soniox show who is talking at a family dinner?
Yes. With speaker diarization on, Soniox labels the text Speaker 1, Speaker 2 and so on, and you can rename speakers after saving; Soniox's pages don't say it remembers a voice in later recordings. Captio AI labels each speaker from one phone. On iPhone, Recognize Voices shows the names of people whose voices you saved, live and in saved recordings, and on iPhone 16 and later Speaker Direction shows which side of the table a voice comes from.
Can Soniox caption phone calls or Zoom meetings?
Soniox doesn't say how. Its pages mention recording and captioning calls and meetings, but not how the sound of a call on the same phone or computer is captured. Captio AI does not caption phone or video calls; it is made for speech in the room around you.
Does Soniox use my conversations to train its AI?
No, Soniox says. Its help centre says it never uses your audio to train AI, and its privacy policy says customer content isn't used to train its models. Captio AI's privacy policy says your content is never used to train AI models, and audio is not stored on its servers.
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Sources
Every page this comparison uses, with the date we checked it.
Captio AI
- Live Captions - Captio AI on the App StoreApple App Store, checked 28 October 2026
- Captio AI on Google PlayGoogle Play, checked 28 October 2026
- Live CaptionsCaptio AI, checked 28 October 2026
- Recognize Voices: Captions That Show Who Is Talking by NameCaptio AI, checked 28 October 2026
- Speaker Direction: See Where a Voice Is Coming FromCaptio AI, checked 28 October 2026
- Recognize Sounds: Doorbells and Alarms in Your CaptionsCaptio AI, checked 28 October 2026
- Live TranslatorCaptio AI, checked 28 October 2026
- Privacy PolicyCaptio AI, checked 28 October 2026
- AI SummaryCaptio AI, checked 28 October 2026
- Audio TranscriptionCaptio AI, checked 28 October 2026
- Captio AI for AI assistants (llms.txt)Captio AI, checked 28 October 2026
- Captio AI widgets and Live ActivityCaptio AI, checked 28 October 2026
Soniox
- Soniox - Speech to Text AI (App Store, United States)Apple App Store, checked 28 October 2026
- Soniox - Speech to Text AI (Google Play, United States)Google Play, checked 28 October 2026
- Soniox App | Everything you do with voice in your languageSoniox, checked 28 October 2026
- Home | Soniox App Help CenterSoniox, checked 28 October 2026
- Hearing accessibility app for deaf and hard of hearing | Soniox AppSoniox, checked 28 October 2026
- How to transcribe | Soniox App Help CenterSoniox, checked 28 October 2026
- Troubleshooting & FAQ (Mobile App) | Soniox App Help CenterSoniox, checked 28 October 2026
- Pricing | Soniox AppSoniox, checked 28 October 2026
- Improving accuracy | Soniox App Help CenterSoniox, checked 28 October 2026
- Managing & sharing | Soniox App Help CenterSoniox, checked 28 October 2026
- How to translate | Soniox App Help CenterSoniox, checked 28 October 2026
- Privacy & data | Soniox App Help CenterSoniox, checked 28 October 2026
- Getting started (Smart Scribe, Desktop App) | Soniox App Help CenterSoniox, checked 28 October 2026
- Getting started (Mobile App) | Soniox App Help CenterSoniox, checked 28 October 2026
- AI actions (Mobile App) | Soniox App Help CenterSoniox, checked 28 October 2026
- Privacy Policy | SonioxSoniox, checked 28 October 2026
- Plans | Soniox App Help CenterSoniox, checked 28 October 2026
- Using the Desktop App | Soniox App Help CenterSoniox, checked 28 October 2026
Published 28 October 2026. App names and trademarks belong to their owners. This page is not affiliated with or endorsed by the companies it compares.