GPT-5.3-Codex-Spark

“I used GPT-5.5-3-Codex-Spark for ALL the fuzzing, as barely any "thought" is necessary when provided with an efficient harness.”

“found the speed of codex-spark to be important for making progress quickly”

“Spark can run at >1000 tok/s but it's highly limited in it's context window size”

“1000tok/s just fills up the context window”

“very fast but tiny context window and doesn't have good reasoning”

“it's 1000 TPS and from my experience more capable than 5.4 mini”

“it can be surprisingly good and it’s super fast”

“Not quite 17k tok/s, but _very_ fast nonetheless. Worth a look.”

“You can run the new gemini flash or 5.3 codex spark at 1000+tps”

“performance is significantly below that of the regular Codex 5.3, and can only handle a 128k text context window”

“GPT spark got me excited again, but somehow that seems to have faded right back into obscurity.”

“it has much faster inference, might be able to keep up”

“Spark is great for this kind of cleanup work because the feedback loop is so tight”

“it spun around in circles cycling through files and finally abandoned saying it ran out of tokens”

“The explore step with Codex-5.3-Spark and Opus 4.6 Fast both feel incredible.”

“the progress is still incredibly impressive even if 15× is overstated”

“efficiency per token has tanked but it's still faster”

“Observed roughly 5x wall-clock improvement for implementation work.”

“That it’s still significantly faster at the same accuracy is wild.”

“Pretty solid, nothing revolutionary (outside of speed).”

“too dumb for QA in complex codebases (for now)”

“my team still spends hours fixing subtle bugs the model introduces”

“1000+ tok/s changes how you interact with a coding model.”

“Looked fine at first but was utter slop upon further review.”

“It's a large step down on the benchmarks to get lower latency.”

“it's been butchering relatively easy to moderate tasks for me”

“Codex Spark was so fast because it noticed that bluey announces the episode names in the episode”

“It definitely makes more mistakes than Codex-5.3, but the speed is something to behold.”

“I was pleasantly suprised.”

“I think it's rarely worth the extra friction of switching from regular 5.3 to 5.3-spark.”

“The speed is really enjoyable.”

“a fast and light model can do great things”

“Blazing fast but it definitely has a small model feel.”

“Small code edits, like they are presented as the use case here, I can do much better myself”

“Great stuff. People are getting used to agents as the interface for everything”

“Their ability to burn through tokens non-stop for hours, days or weeks without intervention.”

“I have yet to see this (produce anything actually useful).”

“it looks like a leap in speed now”

“This is great for bulk tasks: renaming, finding and searching for things”

“Normal codex it self is sub par compared to opus. This might be even worse”