elevenlabs-cost-tuning | elevenlabs-pack

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elevenlabs-cost-tuning | elevenlabs-pack

ElevenLabs Cost Tuning

Overview

Optimize ElevenLabs costs through model selection (Flash = 50% savings), character-efficient text processing, audio caching, and real-time quota monitoring. ElevenLabs bills by character for TTS and by audio minute for STT.

Prerequisites

ElevenLabs account with usage dashboard access
Understanding of your monthly character consumption
Access to billing at https://elevenlabs.io/app/subscription

Instructions

Step 1: Understand the Billing Model

TTS billing (by character):

Model	Credits per Character	10K Chars Cost	Best For
`eleven_v3`	1.0	10,000 credits	Maximum quality
`eleven_multilingual_v2`	1.0	10,000 credits	High quality + multilingual
`eleven_flash_v2_5`	0.5	5,000 credits	Real-time / budget-conscious
`eleven_turbo_v2_5`	0.5	5,000 credits	Fast + affordable

Other feature billing:

Feature	Billing Basis
Speech-to-Text (Scribe)	Per audio minute
Sound Effects	Per generation
Audio Isolation	1,000 characters per minute of audio
Dubbing	Per source audio minute

Plan character limits:

Plan	Monthly	Price	Cost/1K Chars
Free	10,000	$0	$0
Starter	30,000	$5	$0.17
Creator	100,000	$22	$0.22
Pro	500,000	$99	$0.20
Scale	2,000,000	$330	$0.17

Step 2: Model-Based Cost Reduction

The easiest win: use Flash/Turbo models where quality difference is acceptable.

// src/elevenlabs/cost-aware-tts.ts
type ContentType = "greeting" | "notification" | "narration" | "premium";

function selectCostEffectiveModel(contentType: ContentType): {
  modelId: string;
  costMultiplier: number;
} {
  switch (contentType) {
    case "greeting":
    case "notification":
      // Short, functional audio — Flash is fine
      return { modelId: "eleven_flash_v2_5", costMultiplier: 0.5 };

    case "narration":
      // Content creation — quality matters
      return { modelId: "eleven_multilingual_v2", costMultiplier: 1.0 };

    case "premium":
      // Customer-facing, high-value — max quality
      return { modelId: "eleven_v3", costMultiplier: 1.0 };
  }
}

// Estimate cost before generating
function estimateCharacterCost(text: string, modelId: string): number {
  const multiplier = modelId.includes("flash") || modelId.includes("turbo") ? 0.5 : 1.0;
  return text.length * multiplier;
}

Step 3: Character-Efficient Text Processing

Reduce character count without losing meaning:

// src/elevenlabs/text-optimizer.ts

/**
 * Optimize text for TTS to reduce character count.
 * ElevenLabs counts ALL characters including spaces and punctuation.
 */
export function optimizeTextForTTS(text: string): {
  optimized: string;
  originalLength: number;
  savedCharacters: number;
} {
  const original = text;
  let optimized = text;

  // Remove excessive whitespace (spaces count as characters)
  optimized = optimized.replace(/\s+/g, " ").trim();

  // Remove markdown formatting that doesn't affect speech
  optimized = optimized.replace(/[*_~`#]/g, "");
  optimized = optimized.replace(/\[([^\]]+)\]\([^)]+\)/g, "$1"); // [link](url) → link

  // Remove HTML tags
  optimized = optimized.replace(/<[^>]+>/g, "");

  // Collapse multiple punctuation
  optimized = optimized.replace(/\.{2,}/g, ".");
  optimized = optimized.replace(/!{2,}/g, "!");

  return {
    optimized,
    originalLength: original.length,
    savedCharacters: original.length - optimized.length,
  };
}

Step 4: Real-Time Quota Monitoring

// src/elevenlabs/quota-monitor.ts
import { ElevenLabsClient } from "@elevenlabs/elevenlabs-js";

interface QuotaStatus {
  plan: string;
  used: number;
  limit: number;
  remaining: number;
  pctUsed: number;
  resetsAt: Date;
  daysUntilReset: number;
  dailyBudget: number;    // Characters per day until reset
  projectedOverage: boolean;
}

export async function getQuotaStatus(): Promise<QuotaStatus> {
  const client = new ElevenLabsClient();
  const user = await client.user.get();
  const sub = user.subscription;

  const now = new Date();
  const resetsAt = new Date(sub.next_character_count_reset_unix * 1000);
  const msUntilReset = resetsAt.getTime() - now.getTime();
  const daysUntilReset = Math.max(1, Math.ceil(msUntilReset / 86_400_000));

  const remaining = sub.character_limit - sub.character_count;
  const dailyBudget = Math.floor(remaining / daysUntilReset);

  // Project if current usage rate will exceed limit
  const daysSinceReset = 30 - daysUntilReset;
  const dailyRate = daysSinceReset > 0 ? sub.character_count / daysSinceReset : 0;
  const projectedUsage = dailyRate * 30;

  return {
    plan: sub.tier,
    used: sub.character_count,
    limit: sub.character_limit,
    remaining,
    pctUsed: Math.round((sub.character_count / sub.character_limit) * 1000) / 10,
    resetsAt,
    daysUntilReset,
    dailyBudget,
    projectedOverage: projectedUsage > sub.character_limit,
  };
}

// CLI usage
async function printQuota() {
  const q = await getQuotaStatus();
  console.log(`Plan: ${q.plan}`);
  console.log(`Used: ${q.used.toLocaleString()} / ${q.limit.toLocaleString()} (${q.pctUsed}%)`);
  console.log(`Remaining: ${q.remaining.toLocaleString()} characters`);
  console.log(`Daily budget: ${q.dailyBudget.toLocaleString()} chars/day`);
  console.log(`Resets: ${q.resetsAt.toISOString()} (${q.daysUntilReset} days)`);
  if (q.projectedOverage) {
    console.warn("WARNING: Projected to exceed quota at current usage rate");
  }
}

Step 5: Cost-Aware Request Guard

// Prevent expensive operations when quota is low
export async function guardedTTS(
  text: string,
  voiceId: string,
  contentType: ContentType = "notification"
): Promise<ReadableStream | null> {
  const client = new ElevenLabsClient();
  const { modelId, costMultiplier } = selectCostEffectiveModel(contentType);
  const charCost = text.length * costMultiplier;

  // Check quota
  const quota = await getQuotaStatus();

  if (charCost > quota.remaining) {
    console.error(`Insufficient quota: need ${charCost}, have ${quota.remaining}`);
    return null;
  }

  if (quota.pctUsed > 90) {
    // Force cheapest model when quota is critically low
    console.warn("Low quota — forcing Flash model");
    return client.textToSpeech.convert(voiceId, {
      text,
      model_id: "eleven_flash_v2_5",
    });
  }

  return client.textToSpeech.convert(voiceId, {
    text,
    model_id: modelId,
  });
}

Step 6: Usage Tracking Dashboard

// Track per-request costs for analysis
interface UsageEntry {
  timestamp: Date;
  operation: "tts" | "sts" | "stt" | "sfx" | "isolation";
  modelId: string;
  characterCount: number;
  creditCost: number;
  voiceId: string;
  cached: boolean;
}

const usageLog: UsageEntry[] = [];

function trackUsage(entry: Omit<UsageEntry, "timestamp">) {
  usageLog.push({ ...entry, timestamp: new Date() });
}

function getUsageSummary(days = 30) {
  const cutoff = new Date(Date.now() - days * 86_400_000);
  const recent = usageLog.filter(e => e.timestamp > cutoff);

  return {
    totalCredits: recent.reduce((sum, e) => sum + e.creditCost, 0),
    totalCharacters: recent.reduce((sum, e) => sum + e.characterCount, 0),
    byModel: Object.groupBy(recent, e => e.modelId),
    byOperation: Object.groupBy(recent, e => e.operation),
    cacheHitRate: recent.filter(e => e.cached).length / recent.length,
  };
}

Cost Optimization Checklist

Strategy	Savings	Effort
Flash/Turbo models for non-premium content	50%	Low
Cache repeated audio (greetings, prompts)	80-95% for cached	Medium
Text optimization (remove markdown, whitespace)	5-15%	Low
Quota monitoring with budget alerts	Prevents overages	Medium
Usage-based billing (Creator+ plans)	Avoids hard cutoff	Low
Batch short texts into single requests	Reduces overhead	Low

Error Handling

Issue	Cause	Solution
`quota_exceeded` (401)	Monthly limit hit	Upgrade plan or enable usage-based billing
Unexpected high usage	No monitoring	Implement `getQuotaStatus()` guard
Bill shock	Wrong model in production	Audit `model_id` in all TTS calls
Cache not helping	Unique content	Cache only repeated content (greetings, errors)

Resources

Next Steps

For architecture patterns, see elevenlabs-reference-architecture.