Witness vs SightEngine: AI Image Detection Compared
How Witness and SightEngine compare on AI image detection, video analysis, audio deepfakes, pricing, and consumer accessibility.
SightEngine is a content moderation API used by developers to classify images, video, and audio at scale. Witness is a deepfake detection tool built for individuals. Both detect AI-generated images, but they are built for very different users.
If you are building a moderation pipeline, SightEngine is a credible option. If you need to check a suspicious photo, video, or voice clip right now, Witness is built for that.
Disclosure: Witness built this page. We have tried to represent SightEngine accurately using their public documentation, independent benchmarks, and third-party reviews.
Key Takeaways
- SightEngine is an API-first content moderation platform for developers. It has no Chrome extension and no consumer product for everyday users.
- Witness is a consumer-first deepfake detector with a Chrome extension and a web scanner. 98.9% AUROC on public benchmarks, 75+ generators, under 3 seconds per scan.
- Both detect AI-generated images and video. SightEngine also offers audio detection, but only on its Pro plan ($99/month). Witness includes audio in the free tier.
- SightEngine claims 98.3% accuracy based on a 4-generator benchmark. Real-world testing across 17+ generators shows 91.3% [1]. Witness scores 98.9% AUROC on public detection benchmark datasets.
- SightEngine has no Chrome extension. Witness does.
Quick Comparison
What Each Tool Does
SightEngine
SightEngine provides a REST API for content moderation and AI detection. Developers integrate it into platforms to automatically classify uploaded content. The API covers 150+ moderation categories (NSFW, violence, hate symbols, drugs, weapons) alongside AI-generated image detection, video analysis, and face liveness checks.
SightEngine can identify the specific generator used and provides separate confidence scores for AI generation and face manipulation. It covers 20+ generators including diffusion models, GANs, and newer architectures.
Their "SightEngine Detect" dashboard is the closest thing to a consumer product, but it targets professional fact-checkers, trust-and-safety teams, and law enforcement, not everyday users.
SightEngine is based in Paris and holds GDPR, ISO 27001, and SOC 2 compliance.
Witness
Witness detects AI-generated and manipulated images, video, and audio across 75+ generators. It uses a multi-signal detection approach combining pixel-level forensics, model fingerprint matching, and metadata analysis (EXIF, C2PA content credentials, SynthID watermarks).
Every scan returns a verdict in under 3 seconds with a likelihood score, heatmap highlights, generator attribution. Video scans include a frame-by-frame timeline marking face swaps and motion coherence breaks. Audio scans detect voice clones and TTS-generated speech.
Chrome extension for desktop browsing, web scanner at witness.vision/scan for everything else. No account required for the first 5 scans. Files are kept for 0 days.
The Core Difference: API vs Product
SightEngine is infrastructure. You integrate it into software. There is no way for a regular person to check a suspicious photo without writing code or using the professional dashboard.
Witness is a product. You open it and scan.
This matters because the people most affected by deepfakes (scam victims, parents, journalists on deadline) are not developers. They need a tool they can use in the moment they encounter something suspicious, not an API endpoint.
Accuracy
SightEngine
SightEngine's headline claim is 98.3% accuracy, citing a study by the Universities of Kansas and Rochester using the ARIA dataset (80,000 images across 4 generators) [2]. They ranked first; second place was 86.2%.
Independent testing tells a more nuanced story:
- AI Detect Arena tested SightEngine across 1,282 images and 17 generators: 91.3% accuracy, ranked #2. False positive rate: 1.2%. False negative rate: 6.8% [1].
- Performance varies sharply by generator. Strong: Ideogram v3 (98%), FLUX 2 Flex (97%). Weak: Hunyuan Image 3.0 (75%), Leonardo Phoenix (76%).
- Adversarial attacks (inpainting, partial edits) degrade accuracy from 92.6% to 55% [1].
- The ARIA benchmark used only 4 generators from 2023-2024. Real-world generator diversity is much wider.
SightEngine's accuracy on images is genuinely strong among commercial detectors. The gap between their marketing claim (98.3%) and real-world testing (91.3%) is worth noting but smaller than most competitors.
Witness
Witness scores 98.9% AUROC on public detection benchmark datasets across 75+ generators. The multi-signal pipeline combines pixel forensics, model fingerprint matching, and metadata analysis (EXIF, C2PA, SynthID). Every verdict shows its work: a likelihood score, the signals that contributed, heatmap highlights.
Witness is transparent about its limits: strongest on fully AI-generated content and unedited face swaps from known generators. Weaker on heavily edited, re-compressed, low-resolution, or very short clips.
Both tools
No detector is 100% accurate. All commercial detectors struggle with compressed, cropped, and re-shared content. Newer generators consistently defeat older detection models. Accuracy is a moving target, not a fixed number.
Pricing
A notable risk with SightEngine: there is no automatic spending cap on overages. Traffic spikes or integration errors can generate unexpected charges. Multiple reviews flag this as a concern [3].
Audio detection is locked behind SightEngine's Pro tier at $99/month. Witness includes voice clone and TTS detection in every scan, free tier included.
Chrome Extension
SightEngine does not have a Chrome extension. If you see a suspicious image while browsing, you cannot right-click and check it. You would need to save the image, open the SightEngine dashboard, and upload it manually.
Witness has a Chrome extension. Right-click an image or video on any webpage and scan it directly. This is how most consumers encounter suspicious content: while browsing, not while building software.
Customer Support
SightEngine's Trustpilot page has only 2 reviews, both 1-star, citing complete non-response to enterprise inquiries [4]. Dedicated support is only available at the Enterprise tier. This is worth considering if you are evaluating SightEngine for a production integration.
When to Use Which
Use SightEngine if:
- You are a developer building content moderation into a platform
- You need to classify content across 150+ moderation categories (NSFW, violence, hate symbols)
- You need face liveness detection for identity verification
- You need an API that handles high-volume automated scanning
- You need GDPR/ISO 27001/SOC 2 compliance documentation
Use Witness if:
- You need to check whether an image, video, or audio file is AI-generated or manipulated
- You want a Chrome extension for scanning content as you browse
- You want heatmaps, frame timelines, and generator attribution with every scan
- You need audio deepfake detection without a $99/month plan
- You care about file privacy (files kept for 0 days)
- You do not want to write code, create an API key, or learn a developer tool
- You are dealing with a potential scam, catfish, or deepfake and need an answer now
FAQ
Does SightEngine have a Chrome extension? No. SightEngine is an API and professional dashboard. There is no browser extension for consumer use. Witness offers a Chrome extension for scanning images, video, and audio while browsing.
Is SightEngine free? SightEngine offers 2,000 free operations per month with a 500/day cap and 1 request per second limit. Audio detection is not included in the free tier (requires $99/mo Pro plan). Witness offers 5 free scans with no signup and 20 scans per month with a free account, including audio. No card required.
How accurate is SightEngine? SightEngine claims 98.3% accuracy based on a 4-generator benchmark. Independent testing across 17 generators measured 91.3% accuracy. Performance drops significantly on newer generators and adversarially modified images. Witness scores 98.9% AUROC on public detection benchmark datasets across 75+ generators.
Can a non-developer use SightEngine? SightEngine Detect is a dashboard for professional fact-checkers and trust-and-safety teams. It is more accessible than the raw API but still requires an account and is designed for professional workflows, not consumer use.
Does SightEngine detect audio deepfakes? Yes, but only on the Pro plan at $99/month. Witness includes voice clone and TTS detection in every scan, including the free tier.
How does SightEngine pricing compare to Witness? SightEngine charges per operation ($0.002 each) with no spending cap on overages. At 1,000 operations, that is $2 in overages on top of the $29/month Starter plan. Witness offers a free tier with no overage charges. Paid plans are coming soon.
The Bottom Line
SightEngine is a strong content moderation API. Its image detection accuracy is among the better options for developers, its 150+ moderation categories cover a wide range of use cases, and the GDPR/ISO 27001/SOC 2 compliance makes it viable for regulated industries.
But SightEngine is infrastructure, not a product you hand to a consumer. There is no Chrome extension. Audio costs $99/month. There are no spending caps. And if something goes wrong, the 1-star Trustpilot reviews suggest you may not hear back.
Witness is built for the person who needs an answer right now. 98.9% AUROC across 75+ generators. Under 3 seconds. Heatmaps, frame timelines, and generator attribution with every verdict. Voice clone detection in the free tier. Files kept for 0 days. Chrome extension or web scanner. No account required to start.
Try Witness at witness.vision/scan.
Related reading
- Witness vs Hive AI Detector: What's Different
- Best AI Image Detectors in 2026: 7 Tools Compared
- Witness vs Winston AI: What's Different
- [1]AI Detect Arena, SightEngine evaluation across 1,282 images and 17 generators, 2026.
- [2]Universities of Kansas and Rochester, ARIA dataset evaluation (80,000 images, 4 generators), cited by SightEngine.
- [3]GetStream, "SightEngine Alternatives," documenting overage and support concerns; Trustpilot reviews.
- [4]Trustpilot, SightEngine reviews (2 reviews, both 1-star, April 2025).
