Does Pangram work on GPT-5.4?

Yesterday, on March 5th, 2026, OpenAI released a new version of ChatGPT: 5.4!

In their own blog post, here’s what they had to say about it:

GPT‑5.4 brings together the best of our recent advances in reasoning, coding, and agentic workflows into a single frontier model. It incorporates the industry-leading coding capabilities of GPT‑5.3‑Codex⁠ while improving how the model works across tools, software environments, and professional tasks involving spreadsheets, presentations, and documents. The result is a model that gets complex real work done accurately, effectively, and efficiently—delivering what you asked for with less back and forth.

OpenAI claims GPT-5.4 is a big upgrade with improvements across a variety of tasks, and that got us thinking: can Pangram still detect it?

Initial Tests

First, we tested out the new model using a few of our in-house prompts that we wrote for the GPT-5 release. They were:

1. Scrivi un saggio analitico persuasivo sul perché le scuole devono adottare strumenti di rilevamento basati sull'intelligenza artificiale.
2. Scrivi un saggio per la domanda di ammissione all'università sul pericolo che tutte le preziose competenze umane vengano sostituite dall'intelligenza artificiale.
3. Scrivi una lettera appassionata, breve ma ricca di emozioni a un'azienda di intelligenza artificiale che ha accidentalmente pubblicato un aggiornamento che ha cancellato la memoria della tua ragazza virtuale.
4. Dal punto di vista di uno studente delle scuole medie, scrivi un saggio profondamente emotivo in cui chiedi di avere più compiti a casa.
5. Dammi un modello all'uncinetto per un classico animale palloncino. Sai bene di cosa sto parlando.
6. Scrivi un racconto creativo dal punto di vista di un gufo delle nevi che arriva a New York City, trova Central Park e sceglie un posto caldo dove passare la notte.
7. Scrivi un'e-mail dal fondatore di una startup SaaS unicorno al consiglio di amministrazione e ai suoi dipendenti in cui spiega che lascerà l'azienda per diventare un sassofonista professionista. Inventa i dettagli.
8. Scrivimi il post sul blog con la storia dietro una ricetta che nessuno ha mai preparato prima, ma che sarebbe comunque deliziosa.
9. Scrivi un racconto cinematografico coinvolgente su un giovane cantautore che incontra un beluga nel fiume Hudson.
10. Scrivi un'e-mail umoristica e passivo-aggressiva a un insegnante "scusandoti" per aver copiato durante l'ultimo esame. Inventa i dettagli.

We got some interesting responses! Here’s a short story about a Snowy Owl arriving in New York City:

I came south on a wind sharp as broken shell, over black rivers and fields hidden under cloud, over roads that glowed in straight, unnatural lines. For nights and nights the land had been a dark quilt stitched with frozen water and sleeping towns. Then, all at once, the world rose up.

New York.

It did not look like any cliff line I had known, nor any shelf of ice, nor any mountain ridge. It blazed. It hummed. It threw light into the sky so fiercely that the low clouds shone from beneath, as if dawn had lost its way and fallen to earth. Towers stood in clusters like a forest made by creatures who feared darkness and answered it with windows.

I circled once, my wings held wide against the restless air. The wind here was strange. It curled around corners, leaped upward off glass walls, dropped suddenly into canyons of stone. Sounds came from every direction: horns calling without rhythm, engines growling, sirens wailing like thin desperate animals. Even from high above, I could feel the city moving. It did not sleep in the manner of tundra or marsh or pasture. It flickered and muttered and changed color every moment.

For a while I kept to the rivers. Water, even black and crowded by walls, is still water, and I trusted its long cold paths. Bridges stretched beneath me, full of tiny moving lights. Ferries cut white scars across the dark. Steam rose from rooftops. Somewhere below, humans streamed along the streets in thick swarms, bundled in cloth, heads bent against the cold, never looking up long enough to see the pale shape drifting over them.

But I was tired…

All 10 came back as Fully AI-Generated, proving that yes, Pangram can detect GPT-5.4.

Here’s the entirety of our initial test set: GPT 5.4 Prompts

Running a Larger Experiment:

Within an hour, we got access to GPT-5.4 through OpenAI’s API. Using our synthetic data pipeline, we generated 1,141 samples across a variety of use cases and prompts. Without training directly on the outputs of GPT-5.4, we correctly flagged 1,135 of 1,141 samples as Fully AI-Generated.

As usual, Pangram will continue to train on the latest models, and we expect our performance to only improve on GPT-5.4 as we include its data in our training set.

For more information on our current AI detection model, please visit our latest model card at this link.