AI Models · Open-Source vs Paid

Reka Flash 3 Open vs INMercury 2.5 Paid

Reka Flash 3 vs Mercury 2.5 compared — price per token, context window, multimodality, openness and which to choose. Can the open-source model replace the paid one? Full 2026 breakdown.

Prices & specs refreshed from live data · olud.ai

Open-model prices = cheapest provider via OpenRouter; official maker rates may be higher.

Reka Flash 3OpenRekaai
$0.1 /M input
$0.2 /M outputNo per-token fees if you self-host
TypeOpen-weight
Context window66K tokens
MultimodalNo
Self-hostYes
INMercury 2.5PaidInception
$0.04 /M input
$0.15 /M outputManaged API (no infra to run)
TypeProprietary
Context window260K tokens
MultimodalNo
Self-hostNo
Choose Reka Flash 3 if you want to self-host, keep your data private and skip per-token fees — it's open-weight and runs on your own hardware. Choose Mercury 2.5 if you want frontier capability through a managed API with zero infrastructure to run.

Reka Flash 3 vs Mercury 2.5 specs

SpecReka Flash 3Mercury 2.5Winner
MakerRekaaiInception
TypeOpen-weightProprietaryReka Flash 3
Context window66K tokens260K tokensINMercury 2.5
Input price$0.1/M · free self-host$0.04/MINMercury 2.5
Output price$0.2/M · free self-host$0.15/MINMercury 2.5
Vision / multimodalNoNo
Tool / function callingNoYesINMercury 2.5
Self-hostableYesNo (API only)Reka Flash 3
LicenseOpen weightsProprietaryReka Flash 3

Price gap & when to choose each

Choose Reka Flash 3 if…
  • You want to self-host or run on your cloud
  • You prioritize data privacy & control
  • You are building open or reproducible AI
INChoose Mercury 2.5 if…
  • You want frontier performance through a managed API
  • You need the longer 260K context window
  • You want the lower output price
  • You value reliability & ecosystem
  • You don't want to manage infrastructure

Feature comparison

CapabilityReka Flash 3Mercury 2.5
Open weights (downloadable)
Self-hostable
Runs fully offline
Vision / multimodal
Tool / function calling
1M+ context window

Benchmarks: Reka Flash 3 vs Mercury 2.5

Independent benchmark scores measured by Artificial Analysis. Higher is better (except latency).

Reka Flash 3
Mercury 2.5
Intelligence index
5.6
Math index
33.7
GPQA
52.9%
MMLU-Pro
66.9%
Humanity's Last Exam
4.4%
Long Context Reasoning
0%
LiveCodeBench
43.5%
MATH-500
89.3%
AIME
51%
AIME 2025
33.7%
IFBench
30.4%
τ²-Bench
0%
Terminal-Bench Hard
0%
Speed
85.9 tok/s
Latency
0.88s
Intelligence per $
16

Benchmark data by Artificial Analysis.

How Reka Flash 3 and Mercury 2.5 score

🏆 Best value & openness: Reka Flash 3 (4.0 vs 3.0 / 5)
CriterionReka Flash 3Mercury 2.5
Cost-efficiency5.05.0
Context window3.04.0
Openness5.01.5
Self-hosting5.01.0
Multimodality2.03.5

Scores come from live data — output price (cost), context length, open vs closed weights (openness & self-hosting) and vision/tool support (multimodality). Raw task quality isn't scored here; it depends on your benchmark — see the verdict.

What each model is

Reka Flash 3 Open

Rekaai · Open-weight

Reka Flash 3 is a general-purpose, instruction-tuned large language model with 21 billion parameters, developed by Reka. It excels at general chat, coding tasks, instruction-following, and function calling. Featuring a...

Mercury 2.5 Paid

Inception · Proprietary

Mercury 2.5 is the fastest reasoning LLM, and the latest diffusion LLM (dLLM) from Inception. Instead of generating tokens sequentially, Mercury 2.5 produces and refines multiple tokens in parallel, achieving...

Other models in these families

These variants are tracked but not compared here — one page per family keeps the comparison readable.

Other variants tracked
Reka Edge

Frequently asked questions

Is Reka Flash 3 as good as Mercury 2.5?

Reka Flash 3 is open-weight and competitive on many tasks, but Mercury 2.5 may still lead on the hardest reasoning and agentic work. The gap keeps narrowing — benchmark both on your actual use case before deciding.

Can I run Reka Flash 3 locally?

Yes. Reka Flash 3 has open weights, so you can self-host it on your own GPUs or run it via a low-cost API. Mercury 2.5 is API-only and cannot be self-hosted.

Reka Flash 3 vs Mercury 2.5 — which should I pick in 2026?

Choose Reka Flash 3 if you want to self-host, keep your data private and skip per-token fees — it's open-weight and runs on your own hardware. Choose Mercury 2.5 if you want frontier capability through a managed API with zero infrastructure to run.

People also compare

Explore more open-source AI

Browse the full open-source model leaderboard, thousands of tools and live benchmarks — all in one place.

Open the leaderboard →