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GPT-5.3: token counter & pricing

OpenAI · exact (uses official tokenizer) · pricing as of 2026-05-31.

Provider
OpenAI
API model ID
gpt-5.3-chat-latest
Context window
400,000 tokens
Input price
$1.75 per 1M tokens
Output price
$14.00 per 1M tokens
Tokenizer accuracy
exact (uses official tokenizer)
Pricing as of
2026-05-31

Open the counter to count tokens for GPT-5.3 in real time.

What is GPT-5.3?

GPT-5.3 is the third revision in the GPT-5 line, available in two specialized variants: GPT-5.3 Chat (general conversation, the default gpt-5.3-chat-latest) and GPT-5.3 Codex (coding-tuned, gpt-5.3-codex). Both share the same per-token price: $1.75 input / $14 output per 1M tokens, identical to GPT-5.2 but with material upgrades on conversational and coding benchmarks respectively.

This counter uses the Chat variant as the canonical GPT-5.3 entry since both variants tokenize identically.

How tokens are counted here

OpenAI's o200k_base tokenizer. Browser-side via js-tiktoken. Exact.

Pricing notes

$1.75 input / $14 output per 1M. Cached input $0.175/M.

Same price tier as GPT-5.2, the choice between them is about model behavior, not cost. GPT-5.3's specialized tuning is the differentiator.

When to use GPT-5.3

When not to use it:

Common questions

Should I use Chat or Codex?

Pick by primary workload. Mixed workloads: route per-task. The pricing is identical, so there's no penalty for using both in the same pipeline.

How does GPT-5.3 Codex compare to Anthropic's coding flagship?

Anthropic's coding sweet spot is Claude Sonnet 4.6 at $3/$15, 40% more expensive on output than 5.3 Codex. Sonnet often wins on reading large existing codebases; 5.3 Codex often wins on greenfield generation. Both are competitive, run your own evals.

Cached input on Chat vs Codex?

Same caching rate ($0.175/M). The cached-prompt discount works identically across both variants.

Compare GPT-5.3 to other models