AI Data Collection & Annotation for Speech, Text, Image & Video
Synnth delivers production-grade labeled datasets that power accurate, reliable AI models — with human-in-the-loop quality assurance, multilingual coverage, and enterprise-grade security.
Trusted by AI teams worldwide
50M+
Annotations delivered
98.5%
Average QA accuracy
40+
Languages supported
2K+
Domain expert annotators
48h
Pilot batch turnaround
Our Services
Data collection & annotation
for every modality
Speech & Audio
End-to-end speech data services — from recruiting consented native speakers across 40+ languages to delivering richly annotated audio datasets ready for ASR, TTS, and voice AI training.
Data collection
- Native-speaker recruitment
- Scripted & conversational recording
- Wake word & command capture
- Telephony & far-field sessions
- Multilingual & dialect sourcing
Annotation
- Verbatim transcription
- Speaker diarization
- Phoneme-level labeling
- Sentiment & emotion tagging
- Language & accent ID
Text & NLP
Structured text data — from prompt-response generation and web content sourcing to fine-grained NLP annotation — built for LLM fine-tuning, NER, and classification models.
Data collection
- Prompt & response generation
- Human-written text sourcing
- Multilingual content collection
- Domain-specific corpus building
- Web scraping & data curation
Annotation
- Named entity recognition (NER)
- Sentiment & intent labeling
- Text classification
- Coreference resolution
- Translation QA
Image
Diverse image datasets sourced to your specifications — covering demographics, environments, and edge cases — combined with pixel-precise annotation for computer vision models.
Data collection
- Controlled photo capture campaigns
- Demographically balanced sourcing
- Environmental & edge-case sets
- Medical & industrial imagery
- Synthetic data augmentation
Annotation
- Bounding boxes & polygons
- Semantic segmentation
- Keypoint detection
- Image classification
- Depth & 3D annotation
Video
Purpose-built video datasets recorded across real-world scenarios — dashcams, surveillance, industrial, medical — annotated frame-by-frame for autonomous systems and video AI.
Data collection
- Scenario-based video capture
- Dashcam & CCTV footage sourcing
- Multi-camera rig recording
- Action & gesture video datasets
- Indoor & outdoor environments
Annotation
- Frame-by-frame object tracking
- Temporal action labeling
- Lane & road detection
- Pose estimation
- Scene understanding
Why Synnth
Built for teams that
can't afford bad data
Six things that separate Synnth from generic data labeling
and crowdsourcing marketplaces.
Human-in-the-loop QA
Every automated annotation is reviewed and validated by expert humans. We don't outsource quality to algorithms alone.
99.2%
average QA pass rate
Multilingual coverage
Native-speaker annotators across 40+ languages, including low-resource languages and regional dialects.
40+
languages supported
Domain experts
Our annotator network includes medical professionals, legal experts, engineers, and linguists matched to your specific use case.
200+
domain specialists
Enterprise-grade security
All data encrypted at rest and in transit. GDPR compliant, HIPAA-ready, with SOC 2 and ISO processes in place. NDAs on every engagement.
Fast turnaround SLAs
Pilot batches in 48–72 hours. Enterprise projects with guaranteed SLAs and dedicated project managers for ongoing work.
48h
pilot batch delivery
Custom ontology support
We build annotation schemas, labeling guidelines, and quality rubrics tailored to your model's exact requirements — not generic templates.
Industries
Annotation expertise
across every sector
Autonomous Vehicles
Lane detection, pedestrian tracking, LiDAR point cloud annotation, and traffic sign classification for self-driving systems.
Healthcare AI
Medical image annotation, clinical NLP, radiology report labeling, and HIPAA-compliant data handling by medical professionals.
Conversational AI
Intent labeling, dialogue annotation, and multilingual speech data to power chatbots, virtual assistants, and voice AI.
Retail & E-commerce
Product image classification, attribute tagging, visual search training data, and customer review sentiment annotation.
Financial Services
Document classification, fraud signal labeling, financial NLP, and regulatory compliance data for banking and insurance AI.
Robotics & Industrial
3D point cloud annotation, object detection for factory automation, pose estimation, and sensor fusion training data.
AI teams trust Synnth for production-grade training data
From brief to production-ready training data
Whether you need raw data collected, existing data annotated,
or both — a single streamlined pipeline with quality gates at every step.
Define scope
Tell us your use case, data type, volume, languages, and quality targets. We scope a collection and/or annotation plan with your ML team — custom ontologies, demographic quotas, acoustic specs included.
Collect & source
For data collection projects: we recruit consented participants, run recording sessions, and source diverse, scenario-specific raw data. For annotation-only: upload your existing files via our secure portal or API.
Annotate & QA
Trained domain specialists annotate your data. Every label passes inter-annotator agreement checks, automated validation, and senior reviewer sign-off before leaving our pipeline.
Deliver & iterate
Receive clean, structured datasets in your preferred format (JSON, CSV, XML, COCO, etc.) with a full QA report. Free revisions within scope, ongoing batches on your schedule.
FAQ
Common questions about AI data collection and annotation
Everything you need to know about working with Synnth — from quality and security to pricing and turnaround times.
💡 Can’t find your answer here? Talk to our team — we typically respond within one business day.
What is AI data annotation?
What types of data does Synnth annotate?
How does Synnth ensure annotation accuracy?
What industries do you serve?
Can Synnth handle multilingual annotation projects?
Yes. We support 40+ languages with native-speaker annotators, making us suitable for global NLP, automatic speech recognition, and localisation projects — including low-resource languages.
How is my data kept secure?
What is the typical turnaround time for a project?
How do I get started with Synnth?
What is human-in-the-loop annotation?
How much does data annotation cost?
Can Synnth build custom annotation guidelines for our project?
Yes. We work with your ML team to develop task-specific ontologies, labeling guidelines, and quality rubrics tailored to your model’s exact requirements — not off-the-shelf templates.
Does Synnth offer data collection as well as annotation?
Get started
Start your annotation project today
- Response within 1 business day
- No commitment required to get a quote
- NDA available on request
- Free pilot batch for qualifying projects
- Dedicated project manager assigned
- info@synnth.com
- Mon–Fri, 9am–6pm IST