DeepFlag.ai is a free, open-source AI content detector that analyzes text and images to determine whether they were generated by an AI. It combines multiple detection signals into a single confidence score with a transparent per-metric breakdown. No sign-up is required.

How does AI text detection work?

Text detection uses a weighted ensemble of four signals: perplexity scoring, burstiness analysis, entropy measurement, and a RoBERTa-based ML classifier. Each signal contributes to a final confidence score from 0 to 100%.

How does AI image detection work?

Image detection runs FFT frequency analysis, EXIF metadata inspection, and a dedicated image classifier model trained on real versus AI-generated images. All three signals are combined into one confidence score.

Is my text or image stored or used for training?

No. All content submitted is processed in real time and immediately discarded. DeepFlag.ai does not store, log, or use your submissions for model training.

Is DeepFlag.ai free to use?

Yes. The web detector is completely free and requires no sign-up. A Developer API is also available for teams that need to integrate AI detection into their applications.

Does DeepFlag.ai have an API?

Yes. The DeepFlag API is a RESTful service with API key authentication, full OpenAPI documentation, and JSON responses including confidence scores and per-metric breakdowns.

Last updated: May 2026

5 Best Free AI Image Detectors in 2026

Detecting AI-generated images is harder than detecting AI text. The signals are subtler, the generators are diverse (Midjourney, DALL-E, Stable Diffusion, Adobe Firefly, and many others), and image generation technology is advancing rapidly. Still, several techniques provide meaningful detection signals — and the five tools below represent the best current options, from free to enterprise.

How AI Image Detection Works

FFT Frequency Analysis

AI-generated images (especially GAN outputs) often show distinctive patterns in their frequency domain that are invisible to the human eye. Fast Fourier Transform (FFT) analysis converts the image to frequency space and looks for spectral artifacts that real camera images don't produce.

EXIF Metadata Inspection

Camera-taken photos embed metadata — camera model, GPS, timestamp, lens info. AI-generated images often lack this metadata entirely or contain metadata that doesn't match the claimed source. Some tools (Adobe Firefly, C2PA-compatible generators) embed AI-origin watermarks in EXIF/IPTC fields that detectors can read directly.

GAN & Diffusion Artifact Classifiers

Neural classifiers trained on large datasets of real and AI-generated images learn to recognise subtle visual artifacts — over-smooth textures, inconsistent lighting physics, unnatural eye highlights, and diffusion model blurring in fine detail areas like hair and fingers.

Important: Image detection is significantly harder than text detection — all tools in this category have higher error rates than their text counterparts. Treat image detection scores as one signal among many, especially for high-stakes decisions. Detector accuracy degrades as AI generators improve and diversify.

Disclosure: DeepFlag.ai is our own product. It is ranked first because it is the only tool in this list that is completely free with no account required. All competitor data is sourced from public documentation as of May 2026.

DeepFlag.ai

Best Free Image Detector

Free AI image detection using FFT frequency analysis, EXIF inspection, and a neural classifier.

Free

Detection methods

FFT frequency pattern analysisEXIF metadata inspectionGAN/diffusion artifact classifier

Pros

+Completely free — no sign-up, no credit card
+Multi-method approach: frequency analysis + metadata + classifier
+Text + image detection in the same interface
+Open-source — detection methodology is fully auditable
+Zero data retention — your images are never stored

Cons

−Image detection is an active area of improvement
−Less generator-specific coverage than Winston AI
−No mobile AI detection (iPhone/Samsung GenAI)

Best for: Anyone who needs free, private image detection with no account setup

Try Free →

Winston AI

Best Paid Image Detection

The most comprehensive paid image detector — covers Midjourney, SD, Firefly, and mobile AI.

From $10/month

Detection methods

C2PA metadata extractionIPTC watermark analysisGenerator-specific classifiers

Pros

+Broadest generator coverage: Midjourney, Stable Diffusion, DALL-E, Adobe Firefly
+Mobile AI detection: iPhone smart eraser, Samsung GenAI
+C2PA metadata and IPTC watermark extraction
+99.98% claimed accuracy (text and image combined)
+SOC 2 aligned — images never stored per their policy

Cons

−No free tier beyond 14-day trial
−Image scans cost 300 credits each on paid plans
−Starts at $10/month

Best for: Teams that need comprehensive, generator-specific image detection at scale

Visit site →

Copyleaks

Pixel-Level Analysis

Pixel-level AI image detection with visual overlay showing synthetic regions.

From $7.99/month

Detection methods

Pixel-level synthetic region mappingC2PA metadata extractionIPTC watermark analysis

Pros

+Pixel-level overlay highlighting exactly which regions are AI-generated
+C2PA metadata reading — detects Adobe Firefly watermarks
+Mobile AI support: iPhone GenAI, Samsung GenAI
+Detailed forensic report for each image

Cons

−No free tier
−Credit-based pricing — expensive at volume
−Image detection not available on the cheapest plan

Best for: Publishers and media teams that need forensic-level visual reports

Visit site →

Hive Moderation

Enterprise Scale

API-first image detection at millisecond speed — built for platforms.

Enterprise pricing

Detection methods

Deep learning visual classifierSynthetic artifact detectionProbability scoring per image

Pros

+Sub-100ms API response — designed for real-time platform moderation
+Handles images at massive scale
+Returns probability scores for custom risk thresholds
+Audio and video detection available alongside image

Cons

−Enterprise pricing only — no consumer tier
−Requires developer integration
−Not practical for individual or one-off use

Best for: Platforms and marketplaces moderating user-uploaded images at scale

Visit site →

Originality.ai

Best for Publishers

AI image detection bundled with text detection and plagiarism checking.

From $14.95/month

Detection methods

GAN artifact detectionDiffusion model signature analysisMetadata inspection

Pros

+Combined text + image + plagiarism in one workflow
+Image detection for Midjourney, DALL-E, and Stable Diffusion
+Chrome extension for browser-based checking
+Useful for editorial workflows where multiple checks are needed

Cons

−No free tier beyond a 50-credit trial
−Image detection credits cost more than text credits
−API image detection is expensive ($179/month plan)

Best for: Content publishers who need combined AI image, text, and plagiarism detection

Visit site →

Quick Comparison Table

Tool	Free Tier	FFT Analysis	EXIF / C2PA	Mobile AI	Text Detection
DeepFlag.ai	✅ Free	✅	✅	❌	✅
Winston AI	⚠️ Trial only	❌	✅	✅	✅
Copyleaks	❌	❌	✅	✅	✅
Hive Moderation	❌	❌	❌	✅	✅
Originality.ai	⚠️ 50 credits	❌	❌	❌	✅

Pricing and features as of May 2026. Image detection capabilities vary by generator type.

Try DeepFlag.ai Image Detection — Free

Upload any image and get an instant AI detection score. No sign-up, no cost, no data stored.

Try the Detector →

Related Comparisons

DeepFlag vs Winston AI →DeepFlag vs Copyleaks →Best Free AI Detectors →