Blog — OpenRouter Blog

Two Hours of Work That Takes a Week

For Descript, testing a new model was a couple of hours of work and a week of waiting. The team removed the waiting. Evaluations run in an hour or two now, and nobody has to ask an engineer for time. This post covers the queue, what replaced it, and what changed once evaluation ran several times a week.

September 21, 2026

Image Generation Models Compared: Cost, Edit, Quality

Image models are priced per token, per megapixel, or per image, so their listed rates do not compare. We sent the same prompt to 20 of them through the Image API, read usage.cost off each response, and tested text rendering, reference-image editing, seeds, and text-plus-image replies.

September 18, 2026

Build a Reliable Tool-Calling Agent Loop on OpenRouter

A tool-calling agent loop sends the conversation and tool definitions to a model, runs the tool calls the model returns, appends the results, and repeats until the model answers or a stop condition fires. This guide builds that loop in TypeScript with the OpenRouter SDK, then adds an iteration cap, repeated-call detection, model fallback, and history controls.

September 17, 2026

Does DeepSeek V4 Have Vision?

DeepSeek V4 is a family of models, and only some of them accept images. This guide maps every V4 slug on our catalog to its input modalities, shows how to send an image to the two that read images, and shows how to put a vision model in front of the text-only ones.

September 16, 2026

Case Study: How Descript Took New Models Off the Engineering Queue

Descript's Underlord video-editing agent runs 13 production models from Anthropic, Google, OpenAI, and xAI through one OpenRouter integration. Getting a new model through evaluation used to take more than a week. It now takes one to two hours, and the team does it several times a week.

September 15, 2026

LLM-as-a-Judge: Score AI Agent Outputs Automatically

An LLM judge is a second model that scores an agent's output against criteria you write in plain language. This guide explains where a judge fits beside deterministic tests and human review, then shows how to add one to an Ori Eval test, compare candidate models, calibrate the threshold against human-labeled examples, and keep evaluation cost under control.

September 14, 2026

OpenRouter Text-to-Speech: API Tutorial in 5 Minutes

Our OpenAI-compatible speech endpoint puts TTS models from Mistral, xAI, Microsoft, and more behind one request shape. Here's the path from API key to a playable MP3 in cURL, Python, JavaScript, and the OpenAI SDK, plus the response checks that keep JSON errors out of your audio files.

September 11, 2026

Zero Data Retention (ZDR): What It Means for AI APIs

ZDR means an AI provider processes your prompt, returns a response, and doesn't store either one afterward. It's a retention guarantee, not a universal privacy policy. This page explains the boundary, compares ZDR with related controls, and shows how to enforce it at the account, guardrail, or request level.

September 11, 2026

OpenRouter Fusion: How It Works and When to Use It

Fusion is our compound model. It turns one prompt into a short debate among several models: a panel answers in parallel, a judge maps agreement and disagreement, and the calling model writes the final answer. You trade some speed and tokens for quality. This is what it does, what it costs, and when to use it.

September 10, 2026

How to Use OpenRouter Presets: Config-as-Code Guide

A preset is config-as-code for your LLM calls: a named, versioned set of models, system prompts, provider routing, and sampling parameters. Define it once, reference it as @preset/your-slug everywhere, and update every app from the dashboard without a redeploy.