OpenAI's ChatGPT web app shows strong evidence of internal testing for GPT-5, GPT-4L, and

EXHIBIT 753 · FLASH

Aug 15, 2026 16:48 UTC web app https://chatgpt.com

OpenAI's ChatGPT web app shows strong evidence of internal testing for GPT-5, GPT-4L, and various GPT-4o sub-models, along with numerous new feature flags and internal API endpoints.

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Looks like openai is really busy! new strings in chatgpt's web app hint at gpt-5, gpt-4l, and a bunch of gpt-4o variants being tested internally. pretty wild.

major prewire leak for chatgpt: internal mentions of gpt-5, plus gpt-4l and a bunch of gpt-4o-gdrive models. openai is definitely cooking something big for the next generation!

⚠️ FROM WEB-APP BUNDLE — may include vendored-dependency strings, verify before posting. ChatGPT web app (https://chatgpt.com) deployed new frontend code [ab0c15e5f84b9e75 -> 025aed9506b5e57b]: +50739 strings, -1554 strings, 297 interesting [model_id] (22) + /cdn/assets/gpt-details-gt8i8zk7.css + /cdn/assets/gpt-icon-h9k3y3p1.css + GPT-5 + admin/model-access/gpt-5.6-preview + gpt-4 + gpt-4l + gpt-4o + gpt-4o-gdrive + gpt-4o-gdrive-0212 + gpt-4o-gdrive-0314 + gpt-4o-gdrive-1007-mclick + gpt-4o-gdrive-1124 + gpt-4o-gdrive-1124-citation + gpt-4o-mini-filled + gpt-5 + gpt-5-pro + gpt-5-thinking + gpt-5.6-luna-wm + o3-mini-high-in-context-upsell-plus + o4-mini + routes/admin_.model-access.gpt-5[.]6-preview + ve reached the current usage cap for GPT-4. You can continue with the default model now, or try again {formattedTime}. <link>Learn more</link>`,values:{link:YUt,formattedTime:a}}):(0,mG.jsx)($,{id:`TextMessageDisplay.gptUsageCapExceededCustomFeature`,defaultMessage:`You [feature_flag] (128) + ,"data-internal-model-search": + ,action:E,actionMessageDescriptor:pH.focusPromptTextarea,group:kc.Internal,bindings:[{binding:[Lv.Shift,Lv.Escape]}]},{key: + ,e[e.INTERNAL=1]= + ,group:Ooe.Internal,bindings:[{binding:[id.Shift,id.ArrowDown]}],actionMessageDescriptor:Dd({id: + ,group:Ooe.Internal,bindings:[{binding:[id.Shift,id.ArrowUp]}],actionMessageDescriptor:Dd({id: + ,onChange:e=>{f(e.currentTarget.value)},placeholder:u.formatMessage(h4.internalModelsPlaceholder),selectAllOnFocus:!1,value:d}),(0,m4.jsx)( + ,void 0,{surface:e,account_scope:t,is_enabled:String(n)}),q.logStructuredEvent( + /cdn/assets/contentful-dynamic-feature-page-n9a1o41n.js + /cdn/assets/contentful-feature-page-e4jgxsb8.js + /cdn/assets/internal-render-conversation-mwnzm2iz.js + /cdn/assets/internal-render-conversation_.queued-cack1ckg.js + /cdn/assets/internal.widget-studio.open-conversation-imoe7dyk.js + 3VyEPC5dTP_model_instruction