Speech Enhancement API Comparison: Diffio vs ElevenLabs, Krisp, Auphonic & Cleanvoice

The APIs side by side

How each API cleans a recorded file, what it accepts, what an hour costs, and how long it keeps your audio. Prices in US dollars before tax.

"From" prices are the lowest published hourly rate, usually on the largest plan; small one-time purchases cost more per hour. Diffio facts come from our API pricing, quick start, webhooks guide and privacy policy.

How the APIs sounded on the same 59 recordings

Diffio ran each file API below on the same 59 real recordings, through the API where one exists, in its strongest speech cleanup mode at default amounts. Krisp was not tested because it has no file API, and Adobe Podcast lists no API. Scores are model predictions, not a human listening study. Of the 6 API runs, Diffio 4.6 Pro had the largest average quality gain (+2.31) and the lowest word error rate (10.5%); the untouched recordings had a word error rate of 13.2%. Of the other vendors, Cleanvoice came closest on quality (+1.89).

Price per hour

Lowest first: Cleanvoice (from $0.90/h), Auphonic (from $1.36/h), Diffio 4.6 Flash ($5/h), ElevenLabs (from $7.20/h) and Diffio 4.6 Pro ($10/h). Every API priced below Diffio 4.6 Flash had a smaller quality gain in the test: +1.89 for Cleanvoice and +0.82 for Auphonic, against +2.26.

What a request looks like

Short examples from each vendor's documented request shape. Keys come from environment variables; never put them in code.

import os
from diffio import DiffioClient

client = DiffioClient(apiKey=os.getenv("DIFFIO_API_KEY"))
project = client.create_project(filePath="interview.wav")
generation = client.create_generation(
    apiProjectId=project.apiProjectId, model="diffio-4.6-pro"
)
# Poll client.generations.get_progress(...) or wait for the webhook, then:
client.generations.download(
    generationId=generation.generationId, apiProjectId=project.apiProjectId,
    downloadFilePath="restored.mp3", downloadType="mp3",
)

import { DiffioClient } from "diffio"

const client = new DiffioClient({ apiKey: process.env.DIFFIO_API_KEY })
const project = await client.createProject({ filePath: "./interview.wav" })
const generation = await client.createGeneration({
  apiProjectId: project.apiProjectId, model: "diffio-4.6-pro"
})
// Poll client.generations.getProgress(...) or wait for the webhook, then:
const download = await client.generations.getDownload({
  generationId: generation.generationId, apiProjectId: project.apiProjectId, downloadType: "audio"
})

curl -X POST https://api.elevenlabs.io/v1/audio-isolation \
  -H "xi-api-key: $ELEVENLABS_API_KEY" \
  -F "audio=@interview.wav" \
  --output isolated.mp3

curl -X POST https://auphonic.com/api/simple/productions.json \
  -H "Authorization: bearer $AUPHONIC_API_KEY" \
  -F "input_file=@interview.wav" \
  -F "denoise=true" -F "denoisemethod=speech_isolation" \
  -F "action=start"

curl -X POST https://api.cleanvoice.ai/v2/edits \
  -H "X-API-Key: $CLEANVOICE_API_KEY" -H "Content-Type: application/json" \
  -d '{"input": {"files": ["https://example.com/interview.wav"],
       "config": {"remove_noise": true, "studio_sound": true}}}'

# Every call sends: Authorization: Bearer $DESCRIPT_API_TOKEN
POST https://descriptapi.com/v1/jobs/import/project_media   # import the file
POST https://descriptapi.com/v1/jobs/agent    {"project_id": "...", "prompt": "add studio sound to every clip"}
POST https://descriptapi.com/v1/jobs/publish  {"project_id": "...", "media_type": "Audio"}
GET  https://descriptapi.com/v1/jobs/{job_id}  # poll each job; publish returns download_url

Krisp streams 30 ms audio frames over a WebSocket after you exchange an API key for a session token; see its Voice Isolation API overview. Adobe Podcast has no API to call.

Start with the Diffio quick start, then manage keys and usage on the developer dashboard.

Pick by job

• Restore damaged recordings in your product

  Diffio

  Asynchronous jobs with webhooks, Python and JavaScript SDKs, and per-second billing.

• One call, audio back in the response

  ElevenLabs

  Audio isolation returns the cleaned file in the response, for files up to an hour.

• Lowest price per hour, plus leveling or filler-word cuts

  Auphonic or Cleanvoice

  Check the test results for your kind of recording.

• Live calls and voice agents

  Krisp

  Its real-time SDK or streaming API, rather than a file API.

• Transcript editing with an API

  Descript

  Studio Sound runs as an agent edit inside a project.

FAQ

Sources checked October 21, 2026

• ElevenLabs: Audio isolation API reference, Voice Isolator documentation, ElevenLabs API pricing, Zero Retention Mode
• Krisp: Krisp SDK or API, Voice Isolation API overview, Krisp developer pricing, Krisp SDK security
• Auphonic: Auphonic API documentation, Auphonic Simple API, Auphonic webhooks, Auphonic privacy policy, Auphonic pricing
• Cleanvoice: Cleanvoice API v2 documentation, Create an edit, Cleanvoice pricing
• Descript: Descript API help, Descript developer docs, Media minutes and AI credits guide
• Adobe Podcast: Adobe Podcast Enhance Speech, Adobe Firefly Services Audio/Video API
• Diffio: API overview, API pricing, quick start, webhooks, privacy policy

Diffio is not affiliated with or endorsed by Adobe, Descript, Auphonic, ElevenLabs, Cleanvoice or Krisp. Product names are trademarks of their owners.