Gladia  icon
audio-speech

Gladia

Batch STT with rich JSON metadata and strong jargon recall, but weak overlap handling and a channel-duplication caveat on bilingual audio.

Visit Gladia
Batch STTWord timestampsSpeaker labelsMixed-language
TL;DR — our verdictUpdated August 2026 · 8 test artifacts

Strong metadata and jargon recall, but not a clean win on hard overlap

Where it wins
  • You need a batch STT API that returns transcripts plus word-level timestamps, confidence, and speaker labels.
  • You care about technical jargon and proper-term recall on hard audio.
  • You want mixed-language transcript coverage and can rerun stereo or code-switching cases with mono downmix or explicit channel control before trusting the WER.
Main limitation
  • You need reliable overlap handling on crosstalk-heavy audio.
Pricing (verified plans)
Starter (pay-as-you-go) Async $0.61/hr · Real-time $0.75/hrGrowth (annual commitment) Async as low as $0.20/hr · Real-time as low as $0.25/hrEnterprise Custom
Strongest test artifacts

Our take

Gladia is compelling as a batch STT API because it consistently returns word-level metadata and did especially well on the medical jargon sample. But the crosstalk transcript was incomplete, and the bilingual run's WER is not trustworthy because the response duplicated both audio channels; rerun with mono downmix or explicit channel control before relying on that score.

Screen-recording walkthrough of the benchmark workflow on a Mac desktop, moving through Finder, Terminal, and RStudio; it demonstrates the local evaluation process rather than the transcription result itself.

In-Depth Review

Our detailed analysis of Gladia — features, performance, and real-world testing.

AD
AI Demos Team
Expert Reviewer
Verified Review

Feature-by-Feature Breakdown

Batch Transcription
Mixed
Test Summary
Feature tested: Batch Transcription
Result: Partial — Mixed

Feature tested: Batch Transcription

Result: Partial

Verdict: Mixed

Expected behavior: Accepts pre-recorded audio and returns transcripts in batch mode. The tested inputs included three long-form audio samples, showing the endpoint can process multiple recordings in one run.

Test case: Audio file → Text/code file

Input type: Audio file

Input used: Input artifact (Audio file): Overlapping speech / crosstalk sample. — crosstalk.wav

Observed output: Output artifact (Text/code file): Returned a completed transcript for the crosstalk sample, but the scored run was weak: 5,455 words returned against a 7,579-word reference, with WER 37.35%, 529 substitutions, 2,213 deletions, and 89 insertions. — raw-response-3.json

Input artifact: Input artifact (Audio file): Overlapping speech / crosstalk sample. — crosstalk.wav

Output artifact: Output artifact (Text/code file): Returned a completed transcript for the crosstalk sample, but the scored run was weak: 5,455 words returned against a 7,579-word reference, with WER 37.35%, 529 substitutions, 2,213 deletions, and 89 insertions. — raw-response-3.json

What changed: Audio file transformed into Text/code file

Test case: Audio file → Text/code file

Input type: Audio file

Input used: Input artifact (Audio file): Medical jargon narration sample. — medical_terms.mp3

Observed output: Output artifact (Text/code file): Returned a completed transcript for the medical sample with WER 4.07% and 2,738 words against a 2,728-word reference; the run also preserved all scored jargon terms. — raw-response-2.json

Input artifact: Input artifact (Audio file): Medical jargon narration sample. — medical_terms.mp3

Output artifact: Output artifact (Text/code file): Returned a completed transcript for the medical sample with WER 4.07% and 2,738 words against a 2,728-word reference; the run also preserved all scored jargon terms. — raw-response-2.json

What changed: Audio file transformed into Text/code file

Test case: Audio file → Text/code file

Input type: Audio file

Input used: Input artifact (Audio file): Bilingual code-switching sample. — mix_language.mp3

Observed output: Output artifact (Text/code file): Returned a completed transcript for the bilingual sample, but the output duplicated both channels and produced 10,765 words against a 6,517-word reference, so the 88.45% WER is not a trustworthy accuracy result until the run is repeated with mono downmix or explicit channel control. — raw-response.json

Input artifact: Input artifact (Audio file): Bilingual code-switching sample. — mix_language.mp3

Output artifact: Output artifact (Text/code file): Returned a completed transcript for the bilingual sample, but the output duplicated both channels and produced 10,765 words against a 6,517-word reference, so the 88.45% WER is not a trustworthy accuracy result until the run is repeated with mono downmix or explicit channel control. — raw-response.json

What changed: Audio file transformed into Text/code file

Why it matters / Conclusion: Reliable as a batch endpoint, but transcript quality is uneven across hard audio and the bilingual score must be rerun before it can be cited.

Accepts pre-recorded audio and returns transcripts in batch mode. The tested inputs included three long-form audio samples, showing the endpoint can process multiple recordings in one run.

audio/wav
0:00 / 0:00
Loading audio...
Overlapping speech / crosstalk sample.
application/json
raw-response-3.json
Loading file...
Returned a completed transcript for the crosstalk sample, but the scored run was weak: 5,455 words returned against a 7,579-word reference, with WER 37.35%, 529 substitutions, 2,213 deletions, and 89 insertions.
audio/mpeg
0:00 / 0:00
Loading audio...
Medical jargon narration sample.
application/json
raw-response-2.json
Loading file...
Returned a completed transcript for the medical sample with WER 4.07% and 2,738 words against a 2,728-word reference; the run also preserved all scored jargon terms.
audio/mpeg
0:00 / 0:00
Loading audio...
Bilingual code-switching sample.
application/json
raw-response.json
Loading file...
Returned a completed transcript for the bilingual sample, but the output duplicated both channels and produced 10,765 words against a 6,517-word reference, so the 88.45% WER is not a trustworthy accuracy result until the run is repeated with mono downmix or explicit channel control.
Bottom Line
Reliable as a batch endpoint, but transcript quality is uneven across hard audio and the bilingual score must be rerun before it can be cited.
From our researchTranscribe Audio Accurately — Speech-to-Text Engine Benchmarkearlier research
Structured Transcript Output
Strong
Test Summary
Feature tested: Structured Transcript Output
Result: Passed — Strong

Feature tested: Structured Transcript Output

Result: Passed

Verdict: Strong

Expected behavior: Returns machine-readable transcript results with downstream-friendly metadata such as word-level timestamps, confidence values, speaker labels, and channel count. The tested runs on crosstalk, jargon, and bilingual audio showed the structured payload is consistently present and integration-ready.

Test case: Audio file → Text/code file

Input type: Audio file

Input used: Input artifact (Audio file): Overlapping speech / crosstalk sample. — crosstalk.wav

Observed output: Output artifact (Text/code file): Developer metadata was present in the response: word timestamps yes, confidence yes, speaker labels yes, with 12,968 timed tokens and 4 distinct speaker labels. — raw-response-3.json

Input artifact: Input artifact (Audio file): Overlapping speech / crosstalk sample. — crosstalk.wav

Output artifact: Output artifact (Text/code file): Developer metadata was present in the response: word timestamps yes, confidence yes, speaker labels yes, with 12,968 timed tokens and 4 distinct speaker labels. — raw-response-3.json

What changed: Audio file transformed into Text/code file

Test case: Audio file → Text/code file

Input type: Audio file

Input used: Input artifact (Audio file): Medical jargon narration sample. — medical_terms.mp3

Observed output: Output artifact (Text/code file): Developer metadata was present in the response: word timestamps yes, confidence yes, speaker labels yes, with 5,854 timed tokens and 1 distinct speaker. — raw-response-2.json

Input artifact: Input artifact (Audio file): Medical jargon narration sample. — medical_terms.mp3

Output artifact: Output artifact (Text/code file): Developer metadata was present in the response: word timestamps yes, confidence yes, speaker labels yes, with 5,854 timed tokens and 1 distinct speaker. — raw-response-2.json

What changed: Audio file transformed into Text/code file

Test case: Audio file → Text/code file

Input type: Audio file

Input used: Input artifact (Audio file): Bilingual code-switching sample. — mix_language.mp3

Observed output: Output artifact (Text/code file): Developer metadata was present in the response: word timestamps yes, confidence yes, speaker labels yes, with 26,166 timed tokens, 5 distinct speakers, and two channels recorded in the payload. — raw-response.json

Input artifact: Input artifact (Audio file): Bilingual code-switching sample. — mix_language.mp3

Output artifact: Output artifact (Text/code file): Developer metadata was present in the response: word timestamps yes, confidence yes, speaker labels yes, with 26,166 timed tokens, 5 distinct speakers, and two channels recorded in the payload. — raw-response.json

What changed: Audio file transformed into Text/code file

Why it matters / Conclusion: Consistent, integration-friendly metadata export across every tested input.

Returns machine-readable transcript results with downstream-friendly metadata such as word-level timestamps, confidence values, speaker labels, and channel count. The tested runs on crosstalk, jargon, and bilingual audio showed the structured payload is consistently present and integration-ready.

audio/wav
0:00 / 0:00
Loading audio...
Overlapping speech / crosstalk sample.
application/json
raw-response-3.json
Loading file...
Developer metadata was present in the response: word timestamps yes, confidence yes, speaker labels yes, with 12,968 timed tokens and 4 distinct speaker labels.
audio/mpeg
0:00 / 0:00
Loading audio...
Medical jargon narration sample.
application/json
raw-response-2.json
Loading file...
Developer metadata was present in the response: word timestamps yes, confidence yes, speaker labels yes, with 5,854 timed tokens and 1 distinct speaker.
audio/mpeg
0:00 / 0:00
Loading audio...
Bilingual code-switching sample.
application/json
raw-response.json
Loading file...
Developer metadata was present in the response: word timestamps yes, confidence yes, speaker labels yes, with 26,166 timed tokens, 5 distinct speakers, and two channels recorded in the payload.
Bottom Line
Consistent, integration-friendly metadata export across every tested input.
From our researchTranscribe Audio Accurately — Speech-to-Text Engine Benchmarkearlier research
Mixed-Language Transcription
Promising but caveated
Test Summary
Feature tested: Mixed-Language Transcription
Result: Partial — Promising but caveated

Feature tested: Mixed-Language Transcription

Result: Partial

Verdict: Promising but caveated

Expected behavior: Handles mixed English/Spanish audio without requiring a special code-switching flag. The bilingual sample produced Spanish-token coverage, providing evidence for mixed-language coverage.

Test case: Audio file → Text/code file

Input type: Audio file

Input used: Input artifact (Audio file): Spontaneous bilingual Spanish-English conversation. — mix_language.mp3

Observed output: Output artifact (Text/code file): The bilingual run returned 10,765 words against a 6,517-word reference and exposed 56.2% Spanish token recall, but the response duplicated both channels, so the 88.45% WER is an artefact rather than a trustworthy accuracy result. — raw-response.json

Input artifact: Input artifact (Audio file): Spontaneous bilingual Spanish-English conversation. — mix_language.mp3

Output artifact: Output artifact (Text/code file): The bilingual run returned 10,765 words against a 6,517-word reference and exposed 56.2% Spanish token recall, but the response duplicated both channels, so the 88.45% WER is an artefact rather than a trustworthy accuracy result. — raw-response.json

What changed: Audio file transformed into Text/code file

Why it matters / Conclusion: Useful for mixed-language coverage, but this benchmark needs a rerun before the bilingual WER can be trusted.

Handles mixed English/Spanish audio without requiring a special code-switching flag. The bilingual sample produced Spanish-token coverage, providing evidence for mixed-language coverage.

audio/mpeg
0:00 / 0:00
Loading audio...
Spontaneous bilingual Spanish-English conversation.
application/json
raw-response.json
Loading file...
The bilingual run returned 10,765 words against a 6,517-word reference and exposed 56.2% Spanish token recall, but the response duplicated both channels, so the 88.45% WER is an artefact rather than a trustworthy accuracy result.
Bottom Line
Useful for mixed-language coverage, but this benchmark needs a rerun before the bilingual WER can be trusted.
From our researchTranscribe Audio Accurately — Speech-to-Text Engine Benchmark
Speaker-Aware Transcription
Mixed
Test Summary
Feature tested: Speaker-Aware Transcription
Result: Partial — Mixed

Feature tested: Speaker-Aware Transcription

Result: Partial

Verdict: Mixed

Expected behavior: Produces transcript output that preserves speaker labels and works on overlap audio while also continuing through bilingual runs. The tested overlap sample and bilingual runs showed speaker labeling and code-switching coverage in the transcript output.

Test case: Audio file → Image

Input type: Audio file

Input used: Input artifact (Audio file): Four-way overlapping meeting audio (AMI EN2002a), 65.39 MB, 2142.709 s. — crosstalk.wav

Observed output: Output artifact (Image): Run metrics report diarization detected with 4 distinct speaker labels, matching the 4 true participants in EN2002a. — 03-terminal-metrics-3.png

Input artifact: Input artifact (Audio file): Four-way overlapping meeting audio (AMI EN2002a), 65.39 MB, 2142.709 s. — crosstalk.wav

Output artifact: Output artifact (Image): Run metrics report diarization detected with 4 distinct speaker labels, matching the 4 true participants in EN2002a. — 03-terminal-metrics-3.png

What changed: Audio file transformed into Image

Why it matters / Conclusion: Useful for diarization-aware workflows and some mixed-language coverage, but speaker attribution correctness was not measured and the bilingual benchmark needs a rerun before its accuracy can be trusted.

Produces transcript output that preserves speaker labels and works on overlap audio while also continuing through bilingual runs. The tested overlap sample and bilingual runs showed speaker labeling and code-switching coverage in the transcript output.

audio
0:00 / 0:00
Loading audio...
Four-way overlapping meeting audio (AMI EN2002a), 65.39 MB, 2142.709 s.
image
Output artifact for "Speaker-Aware Transcription" test: Run metrics report diarization detected with 4 distinct speaker labels, matching the 4 true participants in EN2002a., 03-terminal-metrics-3.png
Run metrics report diarization detected with 4 distinct speaker labels, matching the 4 true participants in EN2002a.
Bottom Line
Useful for diarization-aware workflows and some mixed-language coverage, but speaker attribution correctness was not measured and the bilingual benchmark needs a rerun before its accuracy can be trusted.
From our researchTranscribe Audio Accurately — Speech-to-Text Engine Benchmarkearlier research

Vendor pricing

Starter matches the list-rate used in the benchmark; Growth lowers the per-hour price on commitment, and Enterprise is custom.

TESTED
Starter (pay-as-you-go)
Async $0.61/hr · Real-time $0.75/hr
€50 free credits one-time; 25 async concurrent requests; 30 real-time concurrent requests; every feature and language included on paid plans.
Growth (annual commitment)
Async as low as $0.20/hr · Real-time as low as $0.25/hr
Requires sales contact; flexible concurrency; custom volume discounts; 99.9% uptime SLA; priority queue; model-training opt-out.
Enterprise
Custom
Requires sales contact; unlimited concurrency; zero data retention; SLAs; custom hosting; custom models; fine-tuning; debundled pricing.

Rates are from the vendor pricing page and differ between async and real-time usage.

✓ Use This If
You need a batch STT API that returns transcripts plus word-level timestamps, confidence, and speaker labels.
You care about technical jargon and proper-term recall on hard audio.
You want mixed-language transcript coverage and can rerun stereo or code-switching cases with mono downmix or explicit channel control before trusting the WER.
✕ Skip This If
You need reliable overlap handling on crosstalk-heavy audio.
You need a trustworthy bilingual WER without first rerunning with mono downmix or explicit channel control.
You need measured streaming latency; this benchmark was batch-only.
audio-speechaudio-to-textspeechOther
Yes. Across all three runs, the response payload exposed word-level timestamps, confidence, and speaker labels, with payload depth 3/3 and timed tokens present.
It did well. The medical jargon run scored WER 4.07% with 73 substitutions, 14 deletions, and 24 insertions, and it recalled all 9 scored jargon terms.
Poorly. On the crosstalk sample it scored WER 37.35% and dropped 2,213 words, although it did detect 4 speaker labels that matched the 4 participants.
No. The bilingual run carried two distinct channel values and duplicated the transcript across channels, so the 88.45% WER is an artefact rather than a valid accuracy score. It should be rerun with mono downmix or explicit channel control.
No. This was a batch benchmark, so the measured latency is wall-clock batch processing time, not streaming lag.
The benchmark used the vendor's list pricing. Starter async is $0.61 per audio-hour ($0.01017/min) and real-time is $0.75 per audio-hour; Growth and Enterprise are lower or custom on the vendor's pricing page.
The mixed-language sample showed Spanish-token coverage without a special code-switching toggle, with 56.2% Spanish token recall. However, the run is still not a trustworthy WER benchmark because the transcript duplicated both channels.

Banner Preview

How the embed badge will look on your site

Gladia  featured on AI Demos

Embed HTML

Copy this code to your website source

<a target="_blank" href="https://aidemos.com/tools/gladia?utm_source=gladia_embed" style="width: 250px; height: 80px; border-radius:4px;" width="250" height="80"> <img src="https://aidemos-website-images.s3.amazonaws.com/featured.png" alt="Gladia | Featured on AI Demos" style="width: 250px; height: 80px; border-radius:4px;" width="250" height="80"> </a>

Quick Integration Guide

  • 1Copy the HTML code block above.
  • 2Paste it into your site's HTML or CMS editor.
  • 3Banner appears instantly on your page.
  • 4Links back to your tool profile here.
Similar Tools

Similar Tools

Discover more AI tools like Gladia to enhance your workflow.

Comments (0)

Please Log in to join the discussion.

Built by FutureSmart AI — the team behind AI Demos

Need a custom AI solution for this use case?

If you are looking to build a custom speech-to-text transcription, audio metadata extraction, or multilingual transcription system for your business or internal workflow, email us at contact@futuresmart.ai.

Get a custom build

Found something inaccurate or missing? We try to keep our AI research accurate and useful. If you found outdated information, an issue, or have a suggestion, email us at collaborate@aidemos.com.

Back to Top