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Transcribe Welsh Audio or Video to Text

Upload any Welsh recording — OpenAI Whisper detects the language automatically and returns an accurate transcript in seconds.

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MP3, WAV, M4A, FLAC · MP4, MOV, MKV, WebM · up to 2 GB

Set language, translation, or vocabulary hints below before transcribing

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YouTube, Dropbox, Google Drive, or any direct MP3/MP4 link

Not applied on Gemini 3.5 Transcribe — the model can't combine vocabulary hints with word-level timestamps

MP3, WAV, M4A, FLAC · MP4, MOV, MKV · up to 2 GB · 10 minutes free every day

Cymraeg · convert.express →

About Welsh transcription

Welsh sits within the Brittonic branch of the Celtic language family, and its grammar produces a phenomenon called consonant mutation, where the opening sound of a word shifts depending on its grammatical relationship to surrounding words. The word for head, for instance, surfaces differently after certain prepositions or possessives — and those shifts are systematic but context-dependent in ways that have no English parallel. Any speech recognition system has to resolve what it hears against a moving target at word boundaries, which is part of why Welsh is genuinely harder to transcribe than languages with more stable word forms. Add to that the limited amount of Welsh audio in most training datasets, and the accuracy picture becomes clearer. Transcripts tend to be more reliable when speakers enunciate carefully and speak at a measured pace rather than conversational speed.

OpenAI Whisper is the only model that supports Welsh on convert.express; MAI-Transcribe 1.5 and Gemini 3.5 Transcribe do not. Welsh is detected automatically from the audio. Upload any Welsh recording up to 2 GB — MP3, WAV, M4A, FLAC, MP4, MOV, and most common audio and video formats are accepted. Every account includes 10 free minutes of transcription per day; longer files are billed at €0.02 per minute with a €0.50 minimum per transaction. Transcripts download as plain text and are automatically deleted within 24 hours of upload.

Basic accuracy

Available transcription models

OpenAI WhisperMAI-Transcribe 1.5 — not supportedGemini 3.5 Transcribe — not supported

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10 min

Free every day

€0.02

Per minute beyond quota

< 1 min

Typical turnaround

Tips for the best results

  • Use a quiet environment — background noise is the biggest source of transcription errors.
  • Speak at a natural pace; extremely fast speech reduces accuracy in any language.
  • MP3 or M4A files work great; uncompressed WAV is ideal for professional recordings.
  • Files up to 2 GB are supported — long recordings are automatically split and merged.

Frequently asked questions

How accurate is AI transcription for Welsh?
Welsh transcription accuracy on convert.express is rated low, and the linguistic reasons are specific. Consonant mutation — a core feature of this Brittonic Celtic language — means the same word can begin with different sounds depending on grammar, which creates real ambiguity for any speech recognition system working from audio alone. Welsh also has relatively limited representation in the training data that underlies most AI transcription tools. Slow, clearly articulated speech produces noticeably better results than fast conversational Welsh.
How long does Welsh transcription take?
Most Welsh recordings are ready in under a minute. Processing time scales with file length — a 10-minute recording typically returns results in 20–40 seconds, and a one-hour recording in around 4–6 minutes. Longer files are automatically split, transcribed in parallel, and merged, so you never need to cut your audio before uploading.
Can I translate Welsh audio to English or other languages?
Yes, two ways. For a quick English-only result, enable "Translate to English" in the upload options above — OpenAI Whisper transcribes and translates Welsh audio to English text in a single pass, at no extra cost. For any other target language, first transcribe normally, then use the Translate action on the finished transcript in your dashboard — it's powered by Claude AI and can translate the Welsh transcript (or its summary and action list) into any of convert.express's other supported languages, not just English.
Which transcription model should I use for Welsh?
Use OpenAI Whisper for Welsh — it is the only model on convert.express that supports this language. OpenAI Whisper is the established choice, with broad language coverage and single-pass translation to English.
What audio and video formats are supported?
MP3, WAV, M4A, FLAC, OGG, Opus, MP4, MOV, MKV, and most other common audio and video formats are accepted. Files up to 2 GB can be uploaded. The language is detected automatically from the audio — no manual language selection is needed.

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Cymraeg · convert.express

Mae Cymraeg yn perthyn i gangen Frythonaidd teulu ieithoedd Celtaidd, ac mae ei gramadeg yn cynhyrchu ffenomen o'r enw treiglad, lle mae sain gyntaf gair yn newid yn dibynnu ar ei berthynas ramadegol â'r geiriau o'i amgylch. Mae'r gair am ben, er enghraifft, yn ymddangos mewn ffurfiau gwahanol ar ôl rhai arddodiaid neu feddiannolyn — ac mae'r newidiadau hynny'n systematig ond yn ddibynnol ar gyd-destun mewn ffordd nad oes cyfatebiaeth iddi yn Saesneg. Rhaid i unrhyw system adnabod lleferydd geisio dehongli'r hyn a glyw yn erbyn targed sy'n symud ar ffiniau geiriau, ac mae hynny'n rhan o'r rheswm pam fod trawsgrifio'r Gymraeg yn wirioneddol anoddach na thrawsgrifio ieithoedd sydd â ffurfiau geiriau mwy sefydlog. At hynny, mae cyfran gymharol fechan o sain Cymraeg yn y rhan fwyaf o setiau data hyfforddi, sy'n egluro pam mae cywirdeb yn gallu amrywio. Mae trawsgrifiadau'n tueddu i fod yn fwy dibynadwy pan fydd siaradwyr yn ynganu'n ofalus ac yn siarad ar gyflymder pwyllog yn hytrach na cham sgwrsio naturiol. OpenAI Whisper yw'r unig fodel sy'n cefnogi'r Gymraeg ar convert.express; nid yw MAI-Transcribe 1.5 na Gemini 3.5 Transcribe yn ei chefnogi. Canfyddir yr iaith yn awtomatig o'r sain. Llwythwch unrhyw recordiad Cymraeg hyd at 2 GB — derbynnir MP3, WAV, M4A, FLAC, MP4, MOV, a'r rhan fwyaf o fformatau sain a fideo cyffredin. Mae pob cyfrif yn cynnwys 10 munud rhad ac am ddim o drawsgrifio y dydd; codir €0.02 y funud am ffeiliau hirach, gyda lleiafswm o €0.50 y trafodiad. Mae trawsgrifiadau'n lawrlwytho fel testun plaen ac yn cael eu dileu'n awtomatig o fewn 24 awr i'w llwytho i fyny.

Pa mor gywir yw trawsgrifio AI ar gyfer y Gymraeg?
Mae cywirdeb trawsgrifio Cymraeg ar convert.express wedi'i raddio'n isel, ac mae'r rhesymau ieithyddol yn benodol. Mae treiglad — nodwedd ganolog o'r iaith Geltaidd Frythonaidd hon — yn golygu y gall yr un gair ddechrau â synau gwahanol yn dibynnu ar y gramadeg, sy'n creu ansicrwydd gwirioneddol i unrhyw system adnabod lleferydd sy'n gweithio o sain yn unig. Mae cynrychiolaeth y Gymraeg hefyd yn gymharol brin yn y data hyfforddi sy'n sail i'r rhan fwyaf o offer trawsgrifio AI. Mae lleferydd araf a chlir yn rhoi canlyniadau sylweddol well na Chymraeg sgwrsio cyflym.
Pa mor hir mae trawsgrifio Cymraeg yn ei gymryd?
Mae'r rhan fwyaf o recordiadau Cymraeg yn barod mewn llai na munud. Mae amser prosesu'n cynyddu gyda hyd y ffeil — mae recordiad 10 munud fel arfer yn dychwelyd canlyniadau mewn 20–40 eiliad, a recordiad awr o hyd mewn tua 4–6 munud. Mae ffeiliau hirach yn cael eu rhannu'n awtomatig, eu trawsgrifio ar yr un pryd, a'u huno wedyn, felly nid oes angen i chi dorri eich sain cyn ei llwytho i fyny.
A allaf gyfieithu sain Cymraeg i'r Saesneg neu ieithoedd eraill?
Gallwch, mewn dwy ffordd. Am ganlyniad Saesneg cyflym, galluogwch yr opsiwn Translate to English yn yr opsiynau llwytho uchod — mae OpenAI Whisper yn trawsgrifio ac yn cyfieithu sain Cymraeg i destun Saesneg mewn un cam, heb unrhyw gost ychwanegol. Ar gyfer unrhyw iaith darged arall, trawsgrifiwch yn gyntaf fel arfer, yna defnyddiwch yr action Translate ar y trawsgrifiad gorffenedig yn eich danfwrdd — mae'n cael ei bweru gan Claude AI ac yn gallu cyfieithu'r trawsgrifiad Cymraeg (neu ei grynodeb a'i restr camau gweithredu) i unrhyw un o ieithoedd eraill a gefnogir gan convert.express, nid Saesneg yn unig.
Pa fodel trawsgrifio ddylwn i ei ddefnyddio ar gyfer y Gymraeg?
Defnyddiwch OpenAI Whisper ar gyfer y Gymraeg — dyma'r unig fodel ar convert.express sy'n cefnogi'r iaith hon. Mae OpenAI Whisper yn ddewis sefydledig, gyda chynhwysiant iaith eang a chyfieithiad un cam i'r Saesneg.
Pa fformatau sain a fideo sy'n cael eu derbyn?
Derbynnir MP3, WAV, M4A, FLAC, OGG, Opus, MP4, MOV, MKV, a'r rhan fwyaf o fformatau sain a fideo cyffredin eraill. Gellir llwytho ffeiliau hyd at 2 GB. Canfyddir yr iaith yn awtomatig o'r sain — nid oes angen dewis iaith â llaw.