Source-tracked model comparison

Claude Mythos 5 vs Claude Opus 4.8: does the limited-access model justify twice the tracked standard token price?

Compare verified pricing and model limits for limited-access premium routing against an available Anthropic baseline. The cost example uses a long-context research workload and does not assume equal model quality.

Direct cost answer: Claude Mythos 5 is estimated at $3,230.00 per month and Claude Opus 4.8 at $1,615.00 for 150,000 input tokens, 5,000 output tokens, and 2,000 monthly requests. Claude Opus 4.8 is $1,615.00 lower under these assumptions. This does not identify a quality winner.
low priorityobserveSources checked 2026-07-14 / 2026-07-12
Pair-specific guidance

Test Mythos 5 against an accessible premium baseline

Mythos 5 carries twice the tracked standard input and output price of Opus 4.8 and is not generally available. Teams with Project Glasswing access should require a workload-specific result before moving traffic from the lower-priced baseline.

Decision factorClaude Mythos 5Claude Opus 4.8
Standard token price$10 input and $50 output per million tokens$5 input and $25 output per million tokens
AvailabilityLimited to approved Project Glasswing customersGenerally available Claude model
Tracked limits1M context and 128k maximum output1M context and 128k maximum output
StackLens assessment

Rollout checks for this pair

  • Keep Opus 4.8 as the cost baseline until Mythos 5 improves a defined acceptance criterion on representative work.
  • Measure the full accepted-task cost because output length and retries can matter more than the input price comparison.
  • Keep a deployment path for users or environments that do not have Project Glasswing access.
Tracked facts

Pricing and model limits

Prices are USD per 1M tokens under each model's verified default profile.

FieldClaude Mythos 5Claude Opus 4.8
ProviderAnthropicAnthropic
API model IDclaude-mythos-5claude-opus-4-8
Input / 1M$10.00$5.00
Cached input / 1M$1.00$0.50
Output / 1M$50.00$25.00
Context window1,000,000 tokens1,000,000 tokens
Maximum output128,000 tokens128,000 tokens
Accepted inputtext, imagetext, image
Example workload

Long-context research cost scenario

150,000 input and 5,000 output tokens per request, 2,000 monthly requests, and 10% cached input.

Anthropic

Claude Mythos 5

$3,230.00 / month
Input cost
$2,730.00
Output cost
$500.00
Per 1,000 calls
$1,615.00
Pricing profile
standard
View model details
Anthropic

Claude Opus 4.8

$1,615.00 / month
Input cost
$1,365.00
Output cost
$250.00
Per 1,000 calls
$807.50
Pricing profile
standard
View model details

Cost result: Claude Opus 4.8 is $1,615.00 lower per month for these assumptions. This is a price comparison, not a model-quality ranking.

StackLens assessment

Questions to answer before choosing

  • Which measured tasks justify Mythos 5's higher standard token rate?
  • Can Opus 4.8 serve as the available baseline for teams without Project Glasswing access?
  • How do completed-task cost, retries, and review time differ on representative workflows?
Workload caveat

What this estimate leaves out

Models whose tracked context window is below the scenario input are excluded from the compatible-model table.

Latency, reliability, output quality, retries, regional processing, and provider-specific tool charges can change the practical decision.