Claude vs ChatGPT API: Which One Cheap Pass?

Di short answer

Claude vs ChatGPT API pricing no get one clear winner, because di gap between both vendors dey change based on di tier and how your tokens mix. As of 21 October 2026, di workhorse tier dey charge di same amount per input token for both sides, but Claude dey charge less per output token. So Claude get small advantage for work wey output tokens plenty. For di frontier tier, OpenAI promotional gpt-5.6-sol rates dey 20% below Claude Opus 5 for every leg. For di small tier, Claude Haiku 4.5 dey cost several times more for di same job. Any answer wey no mention tier and token mix na guess.

So dis page go first show you di arithmetic, then three workloads with cost and token mix, then di multipliers wey fit affect real bill pass di headline rate.

Formula wey you only need

Both APIs dey bill text the same way. You pay for tokens wey you send, and you pay higher rate for tokens wey the model write back.

cost = (input tokens / 1,000,000) * input rate + (output tokens / 1,000,000) * output rate

How much text one token fit hold depend on the model. Anthropic glossary talk say one token na about 3.5 characters of English for Claude Sonnet 4.6, Claude Haiku 4.5 and earlier models. Claude 4.7 and later models, including Opus 5, Sonnet 5, Fable 5 and the 5.5 generation, use newer tokenizer wey dey produce about 30% more tokens for the same text. This mean say na roughly 2.7 characters per token. The familiar figure of about 4 characters, near 0.75 of one word, na OpenAI rule of thumb for its own models, no be Claude own. Use any of these only for first estimate. For real bill, use the counts wey each API return inside the usage object for every response.

# Rates are US dollars per million tokens.
def cost(in_tok, out_tok, in_rate, out_rate):
    return in_tok / 1e6 * in_rate + out_tok / 1e6 * out_rate

# One support-chat turn: 1,400 tokens in, 220 tokens out, on a $2 / $10 model.
print(round(cost(1400, 220, 2.0, 10.0), 6))

The script dey print 0.005, wey be half a cent per turn. Multiply am by the number of turns wey you expect for one month, and you get your budget. If the million-token unit for that denominator still dey look abstract, wetin one million tokens actually fit buy you for Claude go show you concrete amount of text behind am. Learn this one formula, and every price change after today go become one-line edit instead of new analysis.

The published rates, October 2026

Na rates wey dem publish for both vendors' pricing pages, and we check dem on 21 October 2026. This block get every rate wey the scenarios below use. Check am against claude.com/pricing and OpenAI pricing page before you commit budget.

[
  {
    "label": "Frontier",
    "claude_input": 5,
    "claude_output": 25,
    "openai_input": 4,
    "openai_output": 20
  },
  {
    "label": "Workhorse",
    "claude_input": 2,
    "claude_output": 10,
    "openai_input": 2,
    "openai_output": 12
  },
  {
    "label": "Workhorse, Sonnet 4.6",
    "claude_input": 3,
    "claude_output": 15,
    "openai_input": 2,
    "openai_output": 12
  },
  {
    "label": "Small",
    "claude_input": 1,
    "claude_output": 5,
    "openai_input": 0.2,
    "openai_output": 1.2
  }
]

The pairings follow the position for each lineup, no be popularity. Frontier na Claude Opus 5 against gpt-5.6-sol. Workhorse na Claude Sonnet 5 against gpt-5.6-terra. Small na Claude Haiku 4.5 against gpt-5.6-luna. Both vendors still sell higher tiers above this block. For Claude, that tier na Fable 5. E price na double the frontier row for both legs, but e keep the same five-times output ratio. So how much Fable 5 cost and when e deserve that rate worth reading before you assume say Opus 5 na the highest model for your bill. If you compare flagship for one side with budget model for the other side, the result no get useful meaning. Na so most published comparisons take get their headline.

Three things for that block need clear explanation. Sonnet 5 2 and 10 na the standard rates. Anthropic first sell dem as introductory price until 31 August 2026. Later, e make dem standard and cancel the planned increase to $3 and $15. So the workhorse tier remain small Claude advantage. The second workhorse row na the previous generation, Claude Sonnet 4.6. E still list at 3 and 15.

The second thing na the frontier row. On 21 August 2026, OpenAI reduce gpt-5.6-sol from $5 and $30 to 4 and 20 as promotion. The model page talk say the promotional pricing go run at least until 21 November 2026. Until that time, Sol cost 20% less than Claude Opus 5 for input, cache reads, and output. Check this row again after that date.

The third thing na pattern wey you fit remember: Claude prices output at exactly 5 times its own input rate for every row above. OpenAI prices output at 6 times for gpt-5.6-terra and gpt-5.6-luna, and at 5 times for gpt-5.6-sol with the promotional rate. Na this ratio, instead of the absolute rate, dey make the winner change based on your token mix.

Both vendors don also release newer generation than the one this block compare. Anthropic list Claude Opus 5.5 at $4 and $20, Claude Sonnet 5.5 at $2 and $10, and Claude Haiku 5.5 at $0.10 and $0.50 for prompts up to 100,000 tokens. OpenAI model list now start with gpt-6-astra at $10 and $50, gpt-6.1-sol at $2 and $10, and gpt-6-luna at $0.10 and $0.50. These per-token rates dey much closer than the rows above, so for the newer models, the tokenizer and caching sections below go decide the bill. The small-tier picture change pass, and how much Haiku 5.5 cost and where e fit worth reading before you rule Claude out for that tier.

Why rate per million tokens no be the same thing across vendors

Rate na dollar per token. Bill na dollar per token multiply by token count, and token count for one piece of text na property of the model, no be property of the text.

Anthropic explain this directly: Claude 4.7 and later models, wey include Claude Opus 5 and Claude Sonnet 5, dey use newer tokenizer wey dey produce roughly 30% more tokens for the same text than Claude Sonnet 4.6 and earlier. Rate no change. Bill change.

So two rates wey look the same no be two identical bills. Count tokens for both sides with your own text before you trust any comparison, including this one.

curl https://api.anthropic.com/v1/messages/count_tokens \
  -H "x-api-key: $ANTHROPIC_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -H "content-type: application/json" \
  -d '{
    "model": "claude-sonnet-5",
    "messages": [{"role": "user", "content": "Summarise the attached contract."}]
  }'

Healthy response na small JSON object wey hold input_tokens. 401 mean say API key no accept. First check say key variable no empty for your shell, then check say the key itself no malformed, revoked, or expired, because all of dem return the same error. Run the same text through the other vendor tokenizer, divide one count by the other, then multiply that ratio into the published rate before you compare. If the ratio favour one vendor by more than about 1.25, e pass the frontier and workhorse rate differences for the block above. E no near the small tier, where input rates differ fivefold.

Scenario one: chat feature

Support assistant wey dey inside web application. E handle 120,000 turns every month. Each turn dey send system prompt, tool schemas, two retrieved help-desk snippets, and some earlier messages, about 1,400 input tokens altogether. The model dey answer with about 220 tokens. Since e dey interactive, batch discount no fit apply here. Run am for workhorse tier.

[
  {
    "label": "List price",
    "claude_usd": "600.00",
    "openai_usd": "652.80"
  },
  {
    "label": "Cached prefix, 1,100 tokens",
    "claude_usd": "362.40",
    "openai_usd": "415.20"
  },
  {
    "label": "Small tier, same prefix",
    "claude_usd": "300.00",
    "openai_usd": "41.52"
  }
]

For list price, Claude bill na 600.00, while OpenAI bill na 652.80. The input parts dey the same because both input rates dey the same. The whole difference come from output, and Claude win by margin wey too small to use choose vendor.

Now check the stable prefix: the system prompt and tool schemas, about 800 out of the 1,400 input tokens. These ones no dey change between turns. Neither vendor go cache am. Claude Sonnet 5 and gpt-5.6-terra both get minimum cacheable prefix of 1,024 tokens. If the prefix shorter than that, dem go bill am as ordinary input without error. If your stable prefix reach 1,100 tokens, caching go apply for both sides. Since both models charge 10% of their base input rate for cache hit, Claude bill go drop to 362.40, while OpenAI own go drop to 415.20, before the occasional cache write. Caching worth pass vendor choice, and both platforms get am, as long as the prefix reach the minimum.

Na here Claude lose. Most support answers no need workhorse model. Move the same traffic go small tier, and Claude bill go be 300.00, while OpenAI bill go be 41.52. Divide one by the other, and Claude cost about seven times more for the same job. Claude Haiku 4.5 charge 1 per million input tokens, while gpt-5.6-luna charge 0.2. Haiku 4.5 no go cache prefix wey under 4,096 tokens, so the 1,100-token prefix wey gpt-5.6-luna fit cache go dey billed at the full rate for Claude. No amount of caching fit close fivefold gap. If your workload fit small model, OpenAI cheaper for this pairing, and the margin big.

Scenario two: document pipeline wey get long context

25,000 contracts for one month. Every request carry the same 9,000-token instruction and JSON schema, then 12,000 tokens of contract text, and the model return about 700 tokens of structured fields. Output na less than 4% of all the tokens for this job, and na this one fact decide the comparison.

[
  {
    "label": "Chat feature",
    "claude_usd": "362.40",
    "openai_usd": "415.20"
  },
  {
    "label": "Document pipeline",
    "claude_usd": "820.00",
    "openai_usd": "855.00"
  },
  {
    "label": "Coding agent",
    "claude_usd": "116.10",
    "openai_usd": "92.88"
  }
]

With the 9,000-token prefix cached for both sides, Claude bill 820.00 and OpenAI bill 855.00. The input legs match to the cent, because the workhorse input rates match on 21 October 2026. The whole difference na the output leg, wey cost 5 times input for Claude and 6 times for OpenAI.

This job dey use batching too. Both vendors remove 50% from input and output for asynchronous work, so both totals reduce by half and the gap keep the same shape. Batch na the biggest single discount for either platform, and nightly document pipeline fit always use am.

Where Claude lose na the same tier logic as before. Field extraction against a fixed schema na exactly the kind work wey small model dey handle well, and input na 97% of the tokens here. Moving down one tier multiply the OpenAI input rate by 0.1 and the Claude input rate by 0.5. Test the small model on 200 documents before you assume say you need the bigger one, using the same evaluation wey you go run for choosing the correct Claude tier for one job.

Scenario three: agent wey dey code all the time

One developer dey run agent for VPS, roughly 900 model turns every month. Each turn carry about 60,000 input tokens of repository context, and 80% of that na cache hit. E dey produce about 1,800 tokens of edits and explanation. Price am for frontier tier, because na for coding capability gap fit cost real money.

Claude dey bill 116.10, compared with OpenAI wey dey bill 92.88. For the promotional rates, gpt-5.6-sol na 20% cheaper for input, cache reads, and output, so OpenAI win by 20% before cache writes.

That 20% small pass the token-count differences wey tokenizer section warn about. So count tokens for your own repository before you call am, and check again after 21 November 2026, because na the earliest date Sol promotion fit end. Wetin matter pass either rate na the billing model. For one developer with this volume, subscription seat usually cost less than metered API calls, and the whole comparison change once you include one. Work am through with comparison between API and subscription cost before you put agent for metered billing. If you use metering, first learn where the tokens dey go, because token usage of coding agent mostly come from context wey dem resend for every turn, instead of the code wey e write.

The multipliers wey dey decide the bill

The headline rate na the smallest item for this list. Each one wey dey below fit change real bill pass the difference between the two vendors for the same tier.

Cached input. Both vendors charge 10% of base input for cache hit on every model for the rates block above. This no be universal rule: Anthropic's newer Opus 5.5 and Sonnet 5.5 charge 5%, while Fable 5.1 charges 2.5%, and OpenAI's gpt-6.1-sol charges 5%. Both vendors still charge to write the cache. Anthropic charges 1.25 times base input for five-minute entry and 2 times for one-hour entry, and later hit refreshes that entry at the read price. OpenAI charges 1.25 times base input for GPT-5.6 and later models for its default entry. The entry remains reusable for at least 30 minutes after dem write am or last read am. Its Responses API also offers 12-hour entry at 2.5 times base input. So, five-minute entry don pay for itself after one read. Neither vendor caches prefix wey shorter than the model minimum: 1,024 tokens for Claude Sonnet 5 and GPT-5.6, 512 for Claude Opus 5, and 4,096 for Claude Haiku 4.5. Below that limit, you pay full input and get no error. Workload wey get long gaps between requests go write more often than e reads, and caching go cost more than e saves for that case. Steady traffic caches well. Bursty traffic no cache well.

Batch discounts. Both platforms give 50% discount on input and output, but na for asynchronous work only. If the job fit wait, this one go cut the bill for either vendor by half, and e fit combine with caching.

Output share. Claude charges 5 times its input rate for output. OpenAI charges 6 times for gpt-5.6-terra and gpt-5.6-luna, and 5 times for gpt-5.6-sol at its promotional rate. The more of your tokens wey you write instead of read, the better Claude go look when input rate equal. The opposite apply to work wey input dey dominate.

Retries. Retry pays for the whole input again and returns nothing wey you fit use. If 6% of your calls fail schema validation and get retried, your input leg go be 6% larger than your plan talk. Log retries as cost line, not error line. Teams usually discover this multiplier last, and e often bigger than the vendor gap wey dem spend one week arguing about.

Wetin side lose, and where

Claude lose the small tier straight for this pairing. gpt-5.6-luna charge 0.2 per million input tokens, while Claude Haiku 4.5 dey at 1. For output, e dey 1.2 against 5. High-volume classification and short extraction cost four to five times more per token for Claude, and e fit cost more when caching enter matter.

Claude win the workhorse tier for output, 10 against 12 per million for gpt-5.6-terra. But your own token counts fit wipe out that difference. This difference still remain after 1 September 2026, because Anthropic make the Sonnet 5 introductory price become the standard price. Claude lose the frontier tier for now: gpt-5.6-sol promotional 4 and 20 dey 20% below Claude Opus 5 for every leg, at least until 21 November 2026. Neither side win input-dominated work for the workhorse tier, because both sides dey charge 2 per million, so the input legs get the same number.

How to measure dis on your own traffic

Read the usage object for every response and store four numbers for each request: input tokens, output tokens, cache read tokens, and cache write tokens. For Claude API, dem dey show as input_tokens, output_tokens, cache_read_input_tokens, and cache_creation_input_tokens. Add dem together for each day, multiply by the current rates, then compare the total with the invoice. If both numbers no match, na usually retries or code path wey you forget say you release.

Run the comparison with one week of real traffic instead of sample prompt, and compare cost per completed task instead of cost per token. Model wey answer for one attempt at twice the rate fit cheaper than model wey need three attempts at half the rate. Cost per token na rate. Cost per completed task na your bill.

Set a hard spend ceiling before you leave anything running. Both platforms get spend limits for their consoles, and agent wey stick for retry loop fit spend one month budget overnight. Connect am the same way you go connect cost control for agent wey dey always on. If you dey build the first version for server wey you own, first Claude API app for VPS explain the key handling and request loop wey this calculation dey depend on.

FAQ

Claude API cheaper pass ChatGPT API?

No be always so. As of 21 October 2026, workhorse tier dey charge the same amount per input token for both sides, while Claude dey charge less per output token. So, for work wey output plenty, Claude fit cost few percent less for that tier. For frontier tier, OpenAI promotional gpt-5.6-sol rates dey 20% below Claude Opus 5 for every leg, at least until 21 November 2026. For small tier, OpenAI gpt-5.6-luna cost one fifth of Claude Haiku 4.5 per input token, so OpenAI much cheaper for high-volume classification. Calculate your own amount from your own token mix, because your workload, not the price list, go decide differences wey small reach this size.

Why the same words dey cost different number of tokens for each API?

Because every model get its own tokenizer, and na the model determine the token count. Anthropic document say Claude 4.7 and later models produce about 30% more tokens for the same text than Claude Sonnet 4.6 and earlier. Send your own text to each vendor token counting endpoint. Divide one count by the other. Then multiply that ratio by the published rate before you compare dem. A 20% token difference nearly match the rate gaps between frontier and workhorse tiers, so e fit change which one cheaper.

Prompt caching fit ever make the bill bigger?

Yes, for both platforms. For Anthropic, cache write cost 1.25 times the base input rate for a five-minute entry and 2 times for a one-hour entry. OpenAI charge 1.25 times for GPT-5.6 and later with its default 30-minute entry, or 2.5 times for an optional 12-hour entry. For the models we compare here, cache hit cost 0.1 times. If your traffic dey come in bursts and most entries expire before anything read dem, you go pay the write premium but get no reads. Compare cache_creation_input_tokens with cache_read_input_tokens for your logs. Five-minute entry need about one read per write before e pay off, while one-hour entry need about two. If your reads no reach that level, caching dey cost you money: make the entry last longer or remove am.

I suppose run coding agent for the API or use subscription?

For one developer with ordinary usage, subscription seat usually cost less than metered API billing. This na because coding agent dey resend large context for every turn, and dem charge for that context each time. Measure the usage for one week first. Then compare the API total with the seat price. API cheaper when usage dey come in spikes, or when you need programmatic access wey seat no provide. If na hitting usage limit, not price, push you toward API, the ways to get out of Claude usage limit include options wey cost less than switching to metered billing.