Update, October 9, 2026: Since PressBot 1.16.5, Haiku 5.5 is also the default for the Pro admin agent, after our benchmark showed it passing every hard admin task. The “which to use where” section below is updated to match.
Anthropic released Claude Haiku 5.5 on October 7, 2026, and PressBot 1.13.0 supports it as of the same day. It costs $0.10 per million input tokens and $0.50 per million output tokens. Haiku 4.5 cost $1 and $5.
In PressBot terms, a typical visitor conversation dropped from about 2 cents to about a quarter of a cent. If your chatbot handles a few hundred conversations a month, your Anthropic bill for it now rounds to a couple of dollars.
It isn’t quite a 10x saving, though, and the reason is worth knowing before you budget.
What Claude Haiku 5.5 costs in PressBot
The $0.10 / $0.50 rate covers prompts up to 100K tokens. Above that, Haiku 5.5 charges $0.50 input and $2.50 output per million tokens. A visitor chat is nowhere near 100K tokens, so the chatbot always gets the low rate.
| Model | Input (per 1M tokens) | Output (per 1M tokens) | Typical visitor conversation |
|---|---|---|---|
| Claude Haiku 4.5 | $1.00 | $5.00 | About 2 cents |
| Claude Haiku 5.5 | $0.10 | $0.50 | About 0.25 cents |
| Claude Sonnet 5.5 | $2.00 | $10.00 | More than you need for visitor chat |
Why it’s closer to 7–8x than 10x
Haiku 5.5 uses a new tokenizer. The same question and the same answer count as roughly 30% more tokens than they did on Haiku 4.5. The price per token fell by 10x, but each conversation uses more tokens, so the real drop per conversation is about 7 to 8 times.
Here’s what that looks like in monthly API fees:
- 500 conversations a month: under $2 on Haiku 5.5, versus about $10 on Haiku 4.5.
- 1,000 conversations a month: about $3.
PressBot is bring-your-own-key. You pay Anthropic directly at their published rates, and we don’t add a markup or see your AI spend. Anthropic asks for prepaid credits starting at $5, which at these rates covers well over a thousand typical visitor chats.
That changes the math for anyone shopping for the cheapest AI chatbot for WordPress. Claude used to be the pick when you wanted quality and could live with the bill. On Haiku 5.5 it’s also one of the cheapest options, priced the same as GPT-6 Luna.
Haiku 5.5 also has much more room: a 1M-token context window and up to 128K tokens of output, up from 200K and 64K on Haiku 4.5.
What changed in PressBot 1.13.0
Haiku 5.5 now handles the fast, high-volume work inside the plugin:
- Visitor chatbot: it’s the default model for the public chat widget.
- Shield: login-threat analysis runs on it.
- Blog pipeline: the research, strategy and categorizing steps use it.
- Admin agent routing: the step that decides how to handle your request uses it.
- AEO checks and AI-visibility suggestions run on it too.
- No setup: if your site had Haiku 4.5 selected anywhere, the update switches it to Haiku 5.5 for you.
One technical note: Haiku 5.5 “thinks” before answering by default, which adds time and tokens. PressBot turns that off for visitor chat and the quick pipeline steps so replies stay fast and cheap. The admin agent keeps it on, because multi-step site work benefits from it.
Claude Sonnet 5.5 vs Haiku 5.5: which to use where
Claude Sonnet 5.5 came out on September 28, 2026, at $2 / $10 per million tokens, the same price as Sonnet 5. From PressBot 1.12.0 to 1.16.4 it was the default for the Pro admin agent, and it’s still the default for the blog pipeline’s Writer and Critic. We wrote about that release in Sonnet 5.5 Is in PressBot.
The two models are good at different jobs, and PressBot’s defaults split the work between them:
- Haiku 5.5 for visitor chat, quick steps and the admin agent. Visitor conversations are short and frequent, so cost and speed matter most. And since 1.16.5 it runs the admin agent too: on our benchmark it passed every hard admin task, the same score as Sonnet 5.5, at about one eighteenth of the cost.
- Sonnet 5.5 for writing. Drafting and critiquing long posts is where the stronger model’s output is worth the extra cost.
- Opus 5.5 ($4 / $20) or Fable 5.1 ($10 / $50) for the hard jobs. Long, multi-step agent work. Most sites won’t need either day to day.
So when the blog pipeline runs, Haiku 5.5 does the research and categorizing, and Sonnet 5.5 writes and reviews. Your visitors chat on Haiku 5.5 at around $3 per thousand conversations.
How to switch to Claude Haiku 5.5
- Update PressBot to 1.13.0.
- Go to PressBot → Settings and choose Anthropic as the provider, if it isn’t already. Paste your Anthropic API key and make sure your account has prepaid credits.
- Check the chatbot model. Haiku 5.5 is the default. If you had Haiku 4.5 selected, the update already moved it.
- Test it. Open your site in a private window and ask the chatbot a few real questions. After a few days, check your Anthropic usage page to see the actual cost on your traffic.
Next step
If you already run PressBot on Claude, updating to 1.13.0 is all it takes. If you want the admin agent on top of the free chatbot, Pro starts at $29 a year on the PressBot Pro page. Everything else in this release is in the changelog.
